#precalculus

1 messages · Page 300 of 1

warm forum
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Same

viscid thistle
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thanks for the help

warm forum
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It’s 1:33 AM now xD

viscid thistle
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hmm its 12:03 am

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here

warm forum
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,w limit of (sqrt(1-sinx)(tanx-(1/(sqrt2tanx))),x->pi/2

obsidian monolithBOT
warm forum
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Hmm

viscid thistle
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woaj

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nice

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oh wait

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limit does not exist

warm forum
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Probably

viscid thistle
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ok bye and thanks

warm forum
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Ur welc

robust star
viscid thistle
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Well using a+bi, you'll see that a has to be equal to 3 and y has to be equal to -7

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I meant x has to be equal to 3 lol

robust star
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Can someone help me start this?

compact isle
jaunty portal
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hello anyone pls help

viscid thistle
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So I need to find all complex solutions for the following equation: 4x^4-25x^2+36=0

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From synthetic division I found that -2 is a zero. And I got the following equation: 4x^3-8x^2-9x+18

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$(4x^3-8x^2)-(9x+18)$

obsidian monolithBOT
viscid thistle
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$x^2(4x-8)-9(x-2)$

obsidian monolithBOT
viscid thistle
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but i'm struggling to get further from this to find the other solutions

willow bear
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write $x^2(4x-8)$ as $4x^2(x-2)$

obsidian monolithBOT
willow bear
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should be of some help

viscid thistle
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,tex but how did you get this $$ 4x^2(x-2) $$

obsidian monolithBOT
viscid thistle
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nvm

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thanks

plucky perch
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Knowing that:

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Show that the expression below is convergent towards a limit gamma in the interval (0, 1)

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so basically the harmonic series H(n) - ln(n)

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as n goes to infinity

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I'm only allowed to use sequences, so all of this is not in a continuous context

echo wagon
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Do you know monotone convergence theorem?

plucky perch
#

no, can you tell it briefly?

echo wagon
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A sequence that is bounded and monotone (increasing or decreasing) is convergent

mild cloud
echo wagon
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How is that relevant to this question?

plucky perch
echo wagon
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I believe it is increasing not decreasing

plucky perch
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oh yes, the difference is increasing

echo wagon
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No, I'm lying

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It is decreasing

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And a lower bound, yeah that suffices

plucky perch
plucky perch
echo wagon
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There is a clear relationship between terms of the form 1/x and ln(x) with respect to integration

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So look at left/right riemann sums that approximates an integral of 1/x that evaluates to ln(n)

plucky perch
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problem is i cant really use that knowledge into this, im supposed to just use the inequality

echo wagon
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Oh, I didn't see the given inequality

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Can you show it is decreasing using that inequality?

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|| Take a_n and use the given inequality to replace ln(n) with something smaller that results in getting a_(n+1)||

plucky perch
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so replacing ln(n) to get smth smaller we use ln(n+1) - 1/n+1 and the new series is smaller than a_n and we get a_n > a_n+1 so monotone decreasing

south summit
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are you doomed to fail if you aren't familiar with trigonometry and algebra formulas? In precalculus.

devout zinc
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learn them immediately

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especially for limits

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when u will start limits, knowing how to factor is a must

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its essential

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wait, limits is precal or cal 1?

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limits is cal 1

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anyway

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you will learn limits anyway so ye you need to know ur trig and algebra

south summit
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thonkeyes Is there like a AIO formulas sheet preparation

devout zinc
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well like for the start of precal u need to know that cos^2 + sin^2 = 1 and ur trig identities and also double angles

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and also ur factoring formulas

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like diff of squres

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diff of cubes

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sum of cubes

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etc etc

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how to factor by grouping

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u need to know how to deal with abs functions

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how to deal with rationals

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and square roots

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there isnt rlly a formula sheet...

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its pre cal

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in pre cal u get into limits and derivatives

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and u stop there

south summit
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I have a hard time on trig identities without looking at the formulas. Although I do see a very similar relation compared to algebra factoring formulas like a^2 + b^2. Maybe I need to find a way to relate to them easily in my own way.

devout zinc
devout zinc
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cos^2+sin^2 = 1

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the other are derived from dividing by sin^2 and cos^2

stray shuttle
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Hi, I have a question with regards t setting up a precalc problem
Steve and Elsie are camping in the desert, but have decided to part ways. Steve heads north, at 6 AM, and walks steadily at 3 miles per hour. Elsie sleeps in, and starts walking west at 3.5 miles per hour starting at 9 AM.
This is supposed to be solved on a two axis coordinate plane
But I see 3 axis
N/S, E/W, and time
How do I set this up?

south summit
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Damn, these math problems are so dry even the cactus would of died. It's no wonder how the math department isn't able to get anyone interested in mathematics lol.

south summit
# sick steppe Ok and?

Are you mistaking me for attacking Speedbird48's question where I am only address the concern of dry math problems in general?

sick steppe
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No, I just dont see a need for a comment like that

south summit
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There's no need for a comment in search for a better way to learn mathematics?

sick steppe
#

learning and educating are different things, your comment leans more toward a comment on education in my interpretation.

south summit
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Sure, so what's there a no need of?

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and that's determined by you?

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respectfully of course.

hollow lance
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And in what way is your opinion on math problems relevant in any way?

hollow lance
stray shuttle
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I am being helped in another channel but I greatly appreciate you offering help

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I was confused about where to put questions

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Sorry about that

hollow lance
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No worries

south summit
#

I am simply pointing out how math can be uninteresting in hopes someone who understands more in math can challenge my idea into a more well-rounded mindset. So that those who share the notion of math not being very interesting can better understand how to learn math in a more fun or productive manner.

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In a way you can say I'm also seeking for help, but just not directly correlated to specifics of a math problem.

hollow lance
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Challenge these views somewhere else, these are question channels and there are rules on how a user must behave. Consider looking into the social channels

sick steppe
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Again, the pedagogy channel is a place for discussion on pedagogical practices, or any of the discussion channels. I'm not saying I'm the leading figure in pedagogical practices for math, I'm just a teacher candidate.

stuck lark
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i'd like y'all to drop this. the instigating comment itself was unnecessary but blowing up chat over it is much worse

open rock
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Hey all!

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I wanna learn calculus but not sure what prerequisites I should know

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Im good in my algebra, meh in my geometry and have no motherloving clue about trigonometry

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What should I learn?

full pagoda
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definitely trig

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geometry doesn't matter too much when starting in calc, but trig is very important

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so if you don't know that, i suggest learning trig before you start with calc

open rock
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So, what good trig books must a high school sophomore student who studies under a mediocre education system get in order to progress?

full pagoda
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honestly i'd suggest youtube over books

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not only is it free but it's probably easier to understand

viscid thistle
open rock
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Ah, i see

viscid thistle
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and just learn anything that you need to learn as you go

open rock
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Well, i have thomas calculus...

uncut mulch
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you'd need decent knowledge of coordinate geometry

viscid thistle
open rock
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I heard its one of those introductory books, actually

viscid thistle
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I mean in size

open rock
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Nah, im not sure. Ive got a pdf of it and its 800 pages

viscid thistle
open rock
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"introductory"

viscid thistle
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hmm probably also has stuff like multivariable calc and DE's near the end

open rock
#

😔 Wish i knew what all that meant

viscid thistle
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me too dude

open rock
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But is there at least like a list of things to know before I jump in?

viscid thistle
full pagoda
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have you taken precal?

viscid thistle
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well I mean yea

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but I tbh you don't really have to go through all of them

open rock
viscid thistle
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I mean obvious ones being coordinate geometry, and other things you've learnt at school

open rock
#

Yeah... But...

viscid thistle
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trig is pretty important but I just learned it while learning calculus

open rock
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Mediocre education and all

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Im basically self-taught

full pagoda
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i'd suggest precal before calculus lmao

open rock
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huh.

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But...

viscid thistle
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tbh introductory calc really doesn't need that many prereqs ... like the most important would be a good understanding of coordinate geometry and algebra

open rock
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And forgive me for this

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what is precalc

viscid thistle
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pre-calculus

open rock
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yeah

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What is it about ༼;´༎ຶ ۝ ༎ຶ༽

viscid thistle
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preparing for calculus

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stuff like functions, algebra and all that juicy stuff

open rock
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So... Is precalc all ill need 😔

full pagoda
#

it will give you a strong foundation, yes

viscid thistle
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ofc since you don't have the knowledge from precalc it can be quite hard but the internet is a mans best friend

full pagoda
#

though i definitely don't suggest it

open rock
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...

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Im a man of challenge

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but I also take precautions

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ill do both

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Ill learn just enough that I feel comfortable getting in

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But ill also explore the ideas more and interpret what I can from them using my knowledgebase

full pagoda
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trying to learn calc before getting a foundation isn't much of a challenge, more doing yourself a disservice

viscid thistle
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Also there's no point in reading books if you don't also practice

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you can find many excellent problems to solve on the internet

open rock
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Oh, no, no. Of course practice is key

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I just... Have to practice the right way

uncut mulch
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if it's a good intro book, the early chapters should give you some decent reciew

viscid thistle
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yea the book I started out with had a whole chapter on trig and functions and all precalc stuff before beginning

open rock
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Ive got one last request...

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Throighout my high school years we've NEVER dived into graphs

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Not one but

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Bit*

viscid thistle
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but if you have no experience in any precalc topic, you're better off finding a resource designated for precalc

open rock
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So...

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Im worried about my algebra

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What I already dont know

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Im thinking of this

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I need to get:

  • a good algebra book
  • a good precalc book
  • a good trig book

Is this a good approach to this?

full pagoda
#

everything you can find in a book you can probably find on either the organic chemistry tutor's youtube channel or on khan academy

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but if you really want to buy books, go for it

uncut mulch
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don't need an algebra book unless you're doing linear algebra (in which case you'll be using a more advanced one)

open rock
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Buy?

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BUY?

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BAHAHAHAHAHAHAHA

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Zlibrary was my best friend from the day I was born

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yeah, im sorry, man. But I just dont have that kind of finances on me

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Im trying to gather what I can and honestly, pdfs are the only thing im educated from

viscid thistle
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khan academy is free

open rock
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Yeah, but many steer me away from it

viscid thistle
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and an amazing resource

full pagoda
#

just so you know it's against discord TOS to encourage pirating

open rock
#

is it?

viscid thistle
open rock
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Of course i dont, im sorry

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But really, its the only method I have right now

uncut mulch
#

who steers you away from it?

open rock
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Ive got a friend of mine whos into calc alrsady

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He says the calc material in there isnt tip-top

viscid thistle
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ofc one shouldn't rely solely on khan academy but it's a very great resource

uncut mulch
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you shouldn't rely on it completely,
but it's decent enough for an intro into the topic

open rock
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Ah, alright then

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So must I really only rely on precalc and trig?

full pagoda
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rely? no

uncut mulch
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well precalc covers most of early algebra

open rock
#

༎ຶ‿༎ຶ

uncut mulch
#

those will be extremely important when doing calculus

open rock
#

So, so.

#
  • learn precalc
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  • learn trig
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practice both

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And research the topics in calc if I have no idea what theyre on about

uncut mulch
#

pretty much yeh

open rock
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Will my algebra be sufficient, i wonder

viscid thistle
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well good luck

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if you have any questions, well we're here!

open rock
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Thank you! Im glad ive found you all

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Ill be doing what I can from here on out

viscid thistle
viscid thistle
#

6

viscid thistle
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how did you do that

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can you help with this too

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hmm

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im not 100% sure about that one

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oh

viscid thistle
#

b=3, k=6

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b^something = 6

viscid thistle
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it worked

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oh

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omg

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your so good

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do you know how to do this one too

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legit i simplified it

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and it still gives me something with log in it

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do you want me to give my working out for q2 or do u want me to do q3

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w3

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q3

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1/4

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do u want the working out for q3

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yeah can you do these two tho

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those 2 first or the working out for previous questions

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second one is kinda wierd tho i think it either means 5^3-log_5, 7

viscid thistle
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or it means 5^(3-log_5, 7)

viscid thistle
viscid thistle
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damn

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yoru smart

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do you know if the domain is all real numbers

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im pretty sure its allrealnumbers

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but it don't work

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domain and range is my weakness

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oh

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im pretty sure x can be all real numbers in any logarithm

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the base is >0 and != 1

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yes

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so doesn't that mean x = allrealnumbers

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for domain

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my guess would be x=3/2 since log2(2sqrt(2)) = 3/2

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im not 100% sure though

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yeah i got the answer

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i know its x = 3/2

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but its asking for domain

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it thinks domain is wrong

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i think the domain is only x=3/2

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i cant do it too hard for me

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sorry

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oh alright

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its okay though

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you helped a lot

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thanks

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no problem

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do you still want the working out for the previous questions

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or do u want me to skip them

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its fine you don't have to do it

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im gonna spend some time thinking about the domain

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alright

small tree
#

can someone plz help me with this one

willow bear
#

@small tree have you made any progress so far?

small tree
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no i m working on it

willow bear
#

okay. can you post your attempt once you're done or stuck?

devout zinc
#

when it gives u degrees, use trig

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angle a is 35 deg

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u know x = 14

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therefore AC = 14 +r

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u want to find r therefore we have
$sin(35) = \frac{r}{14+r}$

obsidian monolithBOT
#

IAMTHEFARMER

devout zinc
#

because $sin\theta = \frac{opposite}{hypthenuse}$

obsidian monolithBOT
#

IAMTHEFARMER

devout zinc
#

so basically then you have

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$(14+r)sin(35) = r$

obsidian monolithBOT
#

IAMTHEFARMER

#

Result:

-0.42818266949615
devout zinc
#

^ ignore that

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its in rads

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$sin35(14+r) = r$

obsidian monolithBOT
#

IAMTHEFARMER

devout zinc
#

then you will have

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$sin(35)\times 14 + sin35\times r = r$

obsidian monolithBOT
#

IAMTHEFARMER

devout zinc
#

then u solve

shy matrix
#

Are there no ways to find out the equation of a hyperbola if the only given were the center, the vertices, and the transverse axis length?

mental pulsar
#

Could I get some help on this?

uncut mulch
#

what are you being asked to do with that?

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and what's being cut off

mental pulsar
#

oh lmao let me take another

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also I'm being asked to simplify

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Basically this

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I got this far

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I’m stuck

uncut mulch
#

consider conjugates and pythagorean trig identities

mental pulsar
#

I'm not very well versed yet lol, we got this hw after a hour session, this is completely new to me

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so like

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cos^2x + sin^2x = 1 and such?

uncut mulch
#

yes

mental pulsar
#

im still kinda confused

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could you elaborate

uncut mulch
#

start by multiplying the numerator and denominator of your initial fraction by
1 + cos(x); which is the conjugate of the denominator

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and you can apply cos^2(x) + sin^2(x) = 1
to simplify the denominator after that

mental pulsar
#

So like this ?

ocean dune
shy matrix
somber sigil
somber sigil
#

u can sub tan x=sin x/cos x

lavish nacelle
#

can i check for this qn right, i could come up with three equations

  1. cos theta = x / L
  2. 1.8/(2.4 - x) = y/ x
  3. x^2 + y^2 = L^2

so i can manipulate till it’s left with theta and x in equation 1 or theta and L (with two variables)

doing dL/dtheta = 0 would give the correct ans, but does dx/dtheta work? thanks!

#

for differentiation optimization qn, the dy/dx, must the y be referring to the actual thing like here since we wanna maximise length so y has to be L

viscid thistle
devout trail
#

Reposting as requested by Ryam.

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And at the end you just differentiate L(θ) and find the maximum
You'll end up with something like: tan^3(θ) = 1.8/2.4

Posting as requested by Ryam to copy and paste his image and text.

manic rampart
#

Is this supposed to be + 10 since we reflected over x axis

unborn blade
#

when finding the limit as x->inf (sqrt(x+1)/x) we get a case of inf/inf. so at that point i tried dividing each term by the highest term in the denominator which is x

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which gives inf/1 = inf

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but this is wrong

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because apparently i need to rationalize the numerator first

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is there a rule that i basically need to always rationalize the numerator before applying the division by highest power method?

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help appreciated

fierce rain
#

can someone help me with a problem

cunning root
#

ye

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1.5 hours later tho

hollow flint
#

ye

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another 1.5 hours later

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@fierce rain

unborn blade
#

can no one answer mine?

silk summit
#

in a polynomial, can the number of points of discontinuity be defined by the degree of the polynomial? example does the function 4-x^2/4x-x^3 have 3 points of discontinuity?

willow bear
#

might you have fucked up at that stage?

ebon fiber
upper tundra
#

You can push that x inside the sqrt making it x^2 and then the whole inside approaches 0 so, the limit of whole expression is 0.

restive hound
#

Hello, I was just wondering. I’m solving a proving trigonometric identities question, it is 1-tan^2x/1+tan^2x= 1-2sin^2x. I took the pythagorean identity for the denominator so it became 1-tan^2x/ sec^2x. Is it right if I separate these to become 1/sec^2x - tan^2x/sec^2x? For it to become cos^2x - sin^2x ➡️ 1-sin^2x-sin^2x ➡️ 1-2sin^2x ?

willow bear
#

parentheses!!!!!!!

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but yes, aside from the lack of parentheses with plaintext fractions what you're doing is correct.

restive hound
#

Okay, thank you for the reminder!

silent cradle
#

can someone please help me integrate this

restive hound
#

How will I know if two angles are coterminal? I'm given 185 degrees and -545 degrees. Should I subtract 185 to -360 and add 360 to -545?

willow bear
#

subtract your angles from each other

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then see if the difference is a multiple of 360°

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if it is then your angles are coterminal, if it isnt then they are not

restive hound
#

Oh okay, I got -360°. What if I get negative answers but they're multiples of 360°, they wouldn't be counted?

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Like what if I got -720 degrees? it's still wrong?

echo wagon
#

You subtracted 185 and -545 and got -360? Idk how you did it, but no, it doesn't matter

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It just means you subtracted the larger one from the smaller one, instead of the other way around

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If you did it the other way around, you would get the same number but positive

restive hound
#

Yes, I subtracted 185 and -545 and got -360. Was it supposed to be -545-185?

#

So if it doesn't matter if I get an answer that is a negative multiple of 360°, it would still be coterminal then?

restive hound
#

thank you for the help ^^

willow bear
#

,calc 185 - (-545)

obsidian monolithBOT
#

Result:

730
restive hound
#

Thank you!

cobalt warren
#

Can anybody help with this?

uncut mulch
#

have you learned about factor theorem

earnest hull
# cobalt warren

use synthetic division, create the factorable poly, then find the zeros

trim epoch
#

(x-1)(x+2)(cx-d) = Ax^3+Bx^2 +x+6

Expand and compare coefficients

fresh hearth
#

beep boop

hushed pulsar
#

Can someone explains this for me?

(a-2b/a+b) - (2a-b/a+b) = -1

tiny shoal
#

then for the numerator: a-2b-2a+b = -a-b = -(a+b)

#

bring that back in

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-(a+b)/(a+b) = -1

viscid thistle
#

how tf do you graph f(X) = 3x+2 / x-3

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i got like some really sus answers

chrome dove
#

anyone know how to do this?

hushed pulsar
quick hull
# viscid thistle how tf do you graph f(X) = 3x+2 / x-3

The y will be whatever the x going through that comes out as so at -2 it is (-6+2/-2-3 -> -6+2/-5 -> -4/-5 -> 0.8) then -1 (-3+2/-1-3 -> -3+2/-4 -> -1/-4 -> 0.25) 0 is (2/0-3 -> 2/-3) 1 is (3+2/1-3 -> 3+2/-2 -> 5/-2 -> -2.5) and I will finally do 2 (6+2/2-3 -> 6+2/-1 -> 8/-1 -> -8) now you may also notice that 3 is undefined for this function if you wish you could try to use a limit to get what happens as x approaches 3, but I am not going to, so to graph that function you would do exactly what I told you with theoretically every x now this is normally what the calculator is supposed to do for you, but for some reason it seems you want to try it yourself? Either way good luck!

hushed pulsar
tiny shoal
#

And since it’s a-2a + b-2b

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You collectively get -a-b

hushed pulsar
#

Ah thank you!

tiny shoal
#

No worries

fathom phoenix
#

is the answer to this undefined or 2root3/3?

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oh woops i meant this one

devout zinc
#

$csc\theta = \frac{1}{sin\theta}$

obsidian monolithBOT
#

IAMTHEFARMER

devout zinc
#

@fathom phoenix

fresh hearth
#

Hey can someone help me study for my math exam :D

#

<@&286206848099549185>

#

Right now I'm struggling with this question

hushed pulsar
#

Can someone explain;
(x^3-3x^2-10x)/(x+2) = x(x-5)

tiny shoal
#

look carefully at the x variables on the numerator

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see how you can get stuff to move around on the top

hushed pulsar
#

Yeah i'm trying different things

tiny shoal
#

just to start you off, notice how we have x in each term on the numerator

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which allows you to take out x

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so you'll have x(x^2 - 3x - 10)

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on top

hushed pulsar
#

yes i had that

#

x(x^2 - 3x - 10)/(x+2)

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x(1x1x - 3x - 10)

tiny shoal
#

next step would be to reformulate that expression so a (x+2) can pop out and it cancels out with the bottom

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and your leftover would be (x+5)

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so you'll have to factor

hushed pulsar
#

Okay i'll let you know

ebon fiber
#

thats just a graph what is the question

ebon fiber
viscid thistle
#

Can someone show me how to do this?

trim hemlock
#

you would need to determine these things:
Period
Amplitude
An y-intersection

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your equation should be in the form Acos(ax+b) or Asin(ax+b)

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sometimes the a factored out

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but anyway

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the period is to find a, a=2pi/Period

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the Amplitude is to find A, A=Amplitude

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and the y-int is to find b, y-int=Acos(b) or Asin(b), depends on which equation you use

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in some cases, you could also use the x-int to find b, but usually y-int is used because its easier, and quicker

lean hill
#

Could someone explain why the below follows from the first equation?

#

anyone please?

red tree
#

It is merely the result of cross multiplication and collecting it into a polynomial in x

#

That is what I suspect

#

no black magic really

halcyon granite
#

how the hell... i dont get it

lean hill
deep barn
#

hey, so
For a function f(x), you know that f(3) = -8 and f(4) = 3. One zero of f(x) would be located between x= and x= ___

uncut mulch
#

apply ivt

#

also the question should really say continuous function

deep barn
hearty wolf
#

how do you apply the 6 circular functions (e.g., cos, sin, tan, sec, csc, cot) in real life ?

willow bear
#

many ways

#

as one example, consider a building of some height and some distance from you

#

it is possible to (relatively easily) measure the angle of elevation to the top of the building

#

then, if you know either the distance to the building or its height, you can find the other via multiplication by tan(θ) or cot(θ) respectively

#

@hearty wolf does this answer satisfy you?

spark glade
#

why are radius and meters in the same color

#

the blue ink went over v= w *r

silk summit
#

in the question - "at what points on the curve x^2 + y^2 - 2x - 4y + 1 = 0, is the tangent parallel to the y - axis?" ; does " when tangent is parallel to y - axis " indicate that the derivative should be found with respect to y?

willow bear
#

no

#

i mean, you could say that it indicates dx/dy = 0

somber sigil
#

or u can realise that the curve is a circle and centre-coordinates ± radius for x-coordinate is the answer

green kernel
#

How do I solve this? I figured since they were telling us cosΘ is .25, to convert to radians we'd just multiply .25 by (180/pi) but that gives none of the answers in the choices.

willow bear
#

0.25 is not a value in degrees.

#

cos(θ) = 0.25

#

not θ = 0.25

green kernel
#

Ah, I see. Duh lol. They would of given the degree symbol or just said degrees. So, I can just use arccos(.25). The answer is D.

#

Thank you.

willow bear
#

the outputs of trig functions are rarely if ever interpreted as angles in their own right

trim hemlock
#

I think I'm missing the trick here.
Translation: Given y, How many integer m in [-6,6] such that y has 4 asymptotes?
So for sure, y has one asymptote, but now I will have to find a condition for m such that the denominator has 3 unique roots and none of them is x=3. I seem to have hit a roadblock there

#

I mean i do know there is a discriminant for a cubic but i would really really want to stay away from that

hollow lance
#

In either case even when you factor it, you will still have to check each factor so you don't have (x-3) at the bottom

trim hemlock
#

oh, how did you obtain that root? rrt?

hollow lance
#

I mean that was the first thing I thought of doing, because of the (2m^2 + 1)x term

trim hemlock
#

oh right

#

hmmm yeah, did not catch that

#

alright, so its just factoring and checking, thank you

hollow lance
#

np

robust star
strange flare
#

And the factor out polynomial of second degree

robust star
#

I graphed the function and none of these possible roots are true

willow bear
#

are you asked to find the roots?

#

bc it does seem like you're out of luck. all three roots here are kinda nasty

robust star
#

i had a similar issue from a previous test but this problem is asking for something different

echo wagon
#

You don't need the roots then. You need to know Vieta's formulas @robust star

#

Which tells you what the sum/product of the roots are in terms of the coefficients

robust star
#

Is there a way to find the roots?

echo wagon
#

Not really a nice systematic way

#

I mean there are formulas but none that they would expect you to know

#

So it's possible to find them, but you don't need to

robust star
#

I ran into the same issue during a test where it asked me to find the roots. I guess i have to talk to my teacher about it. ty

echo wagon
#

@robust star you are not asked to find the roots

#

You can do the question without finding them

#

That's the point

robust star
#

ik i don't need to find the roots for this problem but in the past I was asked to find the roots.

echo wagon
#

Then possibly there was a way to find them in that question

robust star
#

ill look into it

echo wagon
#

👍

obsidian monolithBOT
#

mechap

lofty epoch
#

How am I supposed to write v_n+1 with v_n

#

where

obsidian monolithBOT
#

mechap

lofty epoch
#

I figured it out :')

merry ledge
#

(x^m)^n = x^mn

obsidian monolithBOT
merry ledge
#

Lol

proud raven
#

i dont like this notation

#

why would you want to do that

#

idk if i trust mashing together set and interval notation but uhh im just a dumbie so idk 😄

grand ember
#

^

willow bear
#

no braces

#

your thing is valid as-is but it'll just evaluate to R because (-∞,5) is not a member of R

nova grove
#

y=-f(x+1)-3

#

the - negative symbol in front of f is reflection across the x axis?

#

so it would be (-x-1, y-3) for mapping notation?

red tree
#

Did you reason through the meaning of the negative symbol or are you asking because you are seeing if the rule you remembered is right?

nova grove
#

seeing if i remembered the rule right @red tree

red tree
#

Ah well the rule actually follows from the definition of a function and the definition of a graph

#

without any further memorization

nova grove
#

ok but did i get it right

red tree
#

Not sure, I forgot the rule

nova grove
red tree
#

What even is mapping notation?

bleak lance
#

F(x)=(x^2-7x+6)/(x^2-2x+1)

#

Where is the graph above the x-axis in interval notation?

#

(-inf,1)?

#

And below? (1,+inf)?

echo wagon
#

F(x) = (x-6)(x-1)/(x-1)^2 = (x-6)(x-1)

#

It will be above the x axis if x-6 and x-1 are either both positive or both negative

#

And it will be below the x axis if the one is positive and the other is negative

#

So your answers should involve both q and 6, not just 1.

radiant elm
#

guys i dont understand log much but our class almost have a test so can u guys explain for me what is log?

full pagoda
#

inverse of exponent

red tree
#

The definition is

The logarithm to the base $a$ of a number $x$, denoted $\log_a(x)$ is the unique number $y$ such that $a^y=x$.

obsidian monolithBOT
#

Icy001

red tree
#

So like, everything you need to know about what log means is in the definition (that's how math works)

radiant elm
#

ty

tranquil haven
#

Hey

#

I don't understand this question

tired axle
prime steeple
#

i just dont understandwhy did we multiply by (n+7)

full pagoda
#

common denominator

tired axle
#

The wiggling emogis on this server are creepy.

prime steeple
full pagoda
#

...common denominator

tired axle
#

You're just mixing up what's new, look again

prime steeple
#

omg pls help i still dont get it

#

like we multipled everything by n+7 but why did we multiply by n+8

uncut mulch
#

common denominator

#

recall the basics for combing fractions through addition/subtraction

#

the LCD is (n+8)(n+7)

prime steeple
#

yep

uncut mulch
#

the frac on the left was multiplied by (n+7)/(n+7) to get that denominator

#

similarly the frac on the right was multiplied by (n+8)/(n+8) to get that same denominator

prime steeple
#

one sec

#

lemme show u

#

@uncut mulch

uncut mulch
#

?

prime steeple
#

im confused like on the right fraction for the numerator we multiplied by (n+8) and for the left one we multiplied by (n+7) why not the right fraction multiplied by n+7?

#

im sorry man im just forgot the common denominator cuz we didnt take this since grade 7

uncut mulch
#

because the right fraction already had (n+7) in the denominator

prime steeple
#

and forgot it

uncut mulch
#

because (n+7)(n+8) = (n+7)(n+8)

#

recall the basics for combing fractions through addition/subtraction

#

starting with something a lot simpler like:
$$\frac 12 + \frac13$$

prime steeple
#

ohhhh

obsidian monolithBOT
#

ℝamonov

prime steeple
#

makes sense now

#

alr alr thanks

nova grove
#

the domain for f(x)=3(x-2)^2-5

#

the domain is {x e R } and range is {y e R | y greater or equal to -5}

#

is this correct?

tired axle
#

$\forall x\in \mathbb{R}$

obsidian monolithBOT
#

Disorganized

tired axle
#

aka $(-\infty,\infty)$

obsidian monolithBOT
#

Disorganized

tired axle
#

...but you know this, just...I just don't want to do my homework.

stuck lark
nova grove
#

,rotate

obsidian monolithBOT
nova grove
#

why is this a compression of 2

#

where did they even get the 2

red tree
#

How sure are you about the order of these things?

nova grove
#

order ? @red tree

tired axle
viscid thistle
tired axle
#

oh!

#

yeah, round braces, scuse me
aaaand the LaTeX won't update. My sins on display forever. ~~

viscid thistle
#

wait no

#

horizontal stretch by a 1/2

#

all x co ordinates divided by a 1/2

#

so they are all multiplied by 2

#

so u can instead say its a compression by 2

nova grove
#

wait

viscid thistle
#

either works

nova grove
#

so i multiply rverything by 2?

viscid thistle
#

yes the x co ordinates

nova grove
#

so 1/2(x +1.5)

viscid thistle
#

so if a point on the curve was (1,5) then itd become (2,5)

red tree
viscid thistle
nova grove
viscid thistle
#

whats the original function that they want to be transformed to this

viscid thistle
#

and anyway you wouldn’t multiply 1.5 by 2, one transformation doesn’t affect the other

#

the transformations only affect the graph you’re transforming

#

so the compression by 2 wouldn’t affect the other horizontal shift to the left by 1.5

nova grove
#

well that’s what my teacher wrote

viscid thistle
#

whats original graph tho

#

thats being transformed

red tree
#

Vertical stretch by a <-> left composition with multiplication by a
Vertical shift by a <-> left composition with addition by a
Horizontal stretch by a<-> right composition with multiplication by 1/a
Horizontal shift by a <-> right composition with addition by -a

viscid thistle
red tree
#

I haven't looked at it closely, although I could figure it out myself. Do you know how to figure it out yourself without appealing to remembering what the teacher said?

#

It's quite possible you never learned how to

viscid thistle
#

ye its whatever is added to x

#

u go left by x units

#

and if something is being minused from x then u go right by x units

viscid thistle
red tree
#

If you figured it out why are you asking me like I have the answer lol

viscid thistle
#

im double checkin if its right

red tree
#

plot the functions on desmos or geogebra to double check

#

lol

viscid thistle
#

im not the one who asked the question so i dont know what the original function was

#

bruh keep up

red tree
#

Well then the whole question is not well defined and your teacher needs some reprimanding, isn't that the conclusion

viscid thistle
#

its not my teacher i didnt send the question

red tree
#

Let's say for the sake of the argument that the original function is x^3

nova grove
#

hey

#

what’s happening

red tree
#

Do you know what the original function was?

nova grove
#

the parent function?

#

it’s a cubic function so f(x)=x^3

red tree
#

ye

#

You can't make sense of this problem without that

nova grove
#

what

red tree
#

Translations and dilations are transformations from one shape to another shape

#

They aren't just properties of a shape

#

if you ask the same question with parent function (x-1)^3, you'll get a different answer

#

Lastly, I said that the meaning of the correct answer is visible if you plot the two functions

#

So consulting the answer key or teacher isn't the main way to check a problem like this

#

(there could be ambiguity in which a horizontal dilation is equivalent to the inverse vertical dilation but you can readily see the functions are the same in these cases)

viscid thistle
#

what r u trying to say i dont get it

bleak lance
#

I dont see 0 as having anything above the x int

#

Because 0 isnt greater than 0

full pagoda
#

what

sick steppe
nova grove
#

i don’t know what you are even saying

red tree
#

No, depends on the problem

#

This is one of those where you should be able to make sense of how to check your answer independently

red tree
#

I'm talking about problem solving strategy and you're talking about credentials

kind arrow
#

why are trig graphs so insane

prime steeple
#

can anyone help

#

please

willow bear
#

@prime steeple do you still need help with this?

prime steeple
#

yes

#

please help

willow bear
#

okay

prime steeple
#

because i have quiz tmr and i cant understand this

willow bear
#

do you know what a geometric sequence is?

prime steeple
#

yes

willow bear
#

okay, what is a geometric sequence?

prime steeple
#

are u questioning me?

#

i just need the solution so i can understand it

willow bear
#

we don't give out solutions

prime steeple
#

why not?

#

okay what do we have to do?

willow bear
prime steeple
#

find a1?

willow bear
#

no, we are not asked to find a1

#

it's not really necessary for this problem either

prime steeple
#

also

#

one more thing

#

need help with this

willow bear
#

anyway, i'm questioning you because i want to find out where exactly you are stuck

#

or have you decided to forfeit the previous question and will instead demand help with this one first?

prime steeple
#

yes i need help with this

willow bear
#

so you no longer care about the geometric sequence question?

prime steeple
#

i do but i need this

#

one

#

first

willow bear
#

.....ok

#

have you ever seen a diagram before similar to the one shown?

prime steeple
#

yes maybe

willow bear
#

so is that a yes or is that a maybe?

prime steeple
#

maybe

willow bear
#

so you have no recollection of seeing such a diagram before?

prime steeple
#

no

#

can u just tell me what is this

#

like

#

what is the teracher trying to explain

willow bear
#

this looks like a tree diagram

#

most likely to do with a probability question

prime steeple
#

hm

willow bear
#

maybe those words could remind you of something

prime steeple
#

explain more?

willow bear
#

there's nothing more to explain, really...

prime steeple
#

is it a common multiple?

willow bear
#

your last question makes zero sense lol

prime steeple
#

k

willow bear
#

you're reading too much into this.

#

with so little detail and such a barebones (literally) diagram there is really nothing more that can be said

tired axle
# prime steeple k

You need to post the complete problem statement if you want help.
You cant drop in on your doctor, show them a picture of the sidewalk, and say "I need help with this". They're not gonna know wtf you are talking about. And neither are we.

BTW the geometric sequence question was solvable, she was just asking what you remembered because she knows what you need to remember to solve that problem

willow bear
#

yeah but somalicock is above such peasant methods

echo wagon
#

I feel like this account is a troll account designed solely to get people to say somalicock

tired axle
tired axle
#

We should ask @JoeBiden or @XiJinping

viscid thistle
#

shouldn't it be 2^3 and 2? how did they distrbuite the 3rd power to the 2 and it became 2^2

hollow lance
obsidian monolithBOT
#

peaceGiant

clever apex
#

how do i graph Quadratic Functions

ionic fractal
#

m(x) = 5x-3 n(x) = x+4

n(m(m(2))) = ?

#

how do i answer this function

full pagoda
#

m(2)=?

ionic fractal
#

thats everything that was given

full pagoda
#

yes, what is m(2)

ionic fractal
#

7

full pagoda
#

so m(2)=7

#

what is m(7)

ionic fractal
#

32

full pagoda
#

n(32)?

ionic fractal
#

36

full pagoda
#

congrats

ionic fractal
#

then how come i got that wrong

#

my module said the answer was 38

#

thank you very muchhh

full pagoda
#

38 is not right

ionic fractal
#

ill probably just suck it up and understand that the module can be wrong sometimes

#

thank you very much tho. didnt clearly understand it.

green kernel
#

The graph is in radians of course. I know the formula y = Atrig(Bx-C)+D. Where A is amplitude, B is the Period, C is Phase Shift, and D is vertical shift.

What I don't know, is what x/2 could possibly be.

uncut mulch
#

x/2 is the product of 1/2 and x

green kernel
#

Ah, yeah, that would make sense. Thank you.

green kernel
#

How would I turn 12/sin60 into it's radical form? The answer is 13.856406460551, but I have no idea how to turn this into it's radical form (8sqrt3).

#

Assuming it's possible because all the answer choices are whole numbers lol.

red tree
#

Did you ever learn what sin(60) is?

green kernel
#

sqrt3 over 2

#

At least on the Unit Circle it is.

uncut mulch
#

apply that and simplify the fraction

#

simplify further
$$= \frac{12}{\br{\frac{\sqrt{3}}{2}}}$$

obsidian monolithBOT
#

ℝamonov

red tree
#

Just to ask, is it that you considered doing this but thought it wasn't allowed?

green kernel
#

I considered this, but got stuck on 24/sqrt3.

red tree
#

24/sqrt(3) is progress, and there is a technique called rationalization of the denominator

green kernel
#

Yea :/, so there is.

#

Forgot all about it because I had to learn it from the internet instead of my teacher.

red tree
#

Teacher didn't teach it?

green kernel
#

Nope. Not a lick. And then decides to toss all whole numbers into the answer choices.

#

I think she assumed this because most current day calculators tell you 12/sin(60) in radical form already, so I can't blame her.

#

I personally don't have one of those calculators.

#

Anyway, I'd get 24sqrt(3) over 3. Then just divide the 24 by the 3 and get 8sqrt(3).

red tree
#

Pretty much

green kernel
#

Thank you.

dim egret
#

Natural draft cooling towers are often shaped as hyperboloids of revolution. Each vertical cross section of these towers is a hyperbola. Suppose that a natural draft cooling tower has the cross section below. Suppose the tower is 450 feet wide at the base, 275 feet wide at the top, and 220 feet at its narrowest point (which occurs 330 feet above the ground.) Determine the height of the tower to the nearest foot.

#

Need help ^

spark glade
#

someone please answer this

#

and show work obv

viscid thistle
#

What have you tried?

#

After you share the original question, please share the work you have completed so far; this will allow someone to help you with wherever you are stuck with the problem.

narrow oasis
#

@viscid thistle is this legal?

#

Basically I want r to be 6.5 on the second loop

viscid thistle
spark glade
#

u are supposed to solve and find the answer

#

crap

#

i didnt writei t correctly

spark glade
#

here it is

#

we need to solve

#

i know the answer is 1

#

but im not sure how they got 1

flint phoenix
#

I don’t care to work through it but that’s the path I’d take to solving it

trim hemlock
#

another way you could do is to apply product to sum identity and simplify

spark glade
cursive imp
#

can someone help with this question

willow bear
#

@cursive imp what is giving you trouble here?

#

is it that the equation of motion as written is actually nonsensical if you think about it physically?

#

(and also that the precision asked for in part b uses the wrong units?)

cursive imp
willow bear
#

the ball is kicked at t=0, not at t=1.

#

sounds like the nonsensical nature of the question went over your head huh

cursive imp
#

what .. so u mean i should used h(0) instead of h(1) for iroc

willow bear
#

yes, but

#

sounds like the nonsensical nature of the question went over your head huh

cursive imp
willow bear
#
  1. there was no need to be this rude. besides, i very clearly gave an answer of 'yes' to your question.
  2. please don't call me 'bro'.
placid knot
#

why are you being impolite to people helping you

#

you get a temporary mute for now, but this type of behavior won't get you very far here

flint phoenix
#

I agree with that decision, but I think saying “the nonsensical nature of the problem went over your head” multiple times can definitely be misinterpreted as condescending. I’m not condoning his response, just saying that I understand why he might have been provoked

viscid thistle
#

How do I go about solving part two of this question? (I don't want the answer; I want guidance)

red tree
willow bear
#

oh? can you link the paper?

red tree
#

Sure give me a couple of minutes

willow bear
#

ty

civic furnace
#

What's the formula for compound interest if the money is withdrawn earlier? I forgot.

say:
5000 for 6 months with 4.4% yearly

#

i guess i just halve it?

mild swan
#

If there is a withdrawal, I'm pretty sure you can just decrease the balance according to the amount withdrawn

civic furnace
#

see

5000 for 6 months with 4.4% yearly

#

we have a yearly interest, but the money is withdrawn in 6 months

#

how do I calculate it?

#

normally the formula is
A = P(1+r/n)^nt
for:
A = amount
P = principal
r = interest rate in decimal
n = number of times interest is compounded per t
t = time

mild swan
#

If t = 1 year, then n = 2 times

civic furnace
#

there's nothing said about n, though?

#

we only care about whatever is left at the end of 6 months

#

i mean

#

i suppose it is implied that n = 2

#

but you still have to calculate only the amount that is left at the end of the 6 months

mild swan
#

Oh, if this is a rate at which money is withdrawn, then I imagine the rate would be negative

civic furnace
#

The money is deposited for 6 months

#

The interest rate is 4.4% yearly

#

You have to calculate how much money will you have given this interest rate after 6 months

#

I'm asking what's the formula

mild swan
#

A = P(1+r/n)^nt
for:
A = amount
P = principal
r = interest rate in decimal
n = number of times interest is compounded per t
t = time

I think this is right, but idk why you're withdrawing money (usually these types of equations don't involve withdrawal)

#

Do you have a picture of the original problem?

civic furnace
#

The original problem isn't in English. I have translated it

#

the principal is 5000
the time is 6 months
the interest rate is 4.4% yearly
calculate the amount after 6 months

mild swan
#

Oh okay

#

In which case there is no withdrawal

#

Just compounding interest: no money is being removed from the bank account

#

If it's compounded yearly, then after 6 months, the balance won't change.

#

The balance will first change (in other words, be different than the initial amount of 500) after 1 year (or 12 months)

civic furnace
#

in such case the question doesn't make sense

#

so it must be something else

#

but regardless

#

thank you for your help

#

i'll ask my teacher about it

willow bear
bleak lance
#

What is 2-x equivalent to?

#

-x+2?

sick steppe
#

$a+b=b+a$

obsidian monolithBOT
copper vigil
#

$a-b = -(b-a)$

obsidian monolithBOT
#

EndTimes

copper vigil
#

@bleak lance that's how you find the zero

nova grove
#

for the number line

#

my teacher just plotted random points that’s greater than 4/3 and less than 4/3 ?

#

then she use points like 2 and 3 using driscrimnate equation?

red tree
#

I would have to say this isn't the best way to present the solution to the problem

#

even though it is pretty step-by-step

#

There is too much "process" here and it obscures the logic

drowsy ledge
#

Hi

#

Could I get help with creating conic sections equations

#

<@&286206848099549185>

drowsy ledge
#

someone please ;-

#

For the circle i made the equation

viscid thistle
#

I am actually here to learn calc but good luck

obsidian monolithBOT
#

Key 𐂂

drowsy ledge
#

I got that for the circle

#

its center is (-1,7)

#

my bad its supposed to be (x-1)

#

The r=2

#

$(x+1)^2+(y-7)^2=4$

obsidian monolithBOT
#

Key 𐂂

drowsy ledge
#

my bad. thats the equation i wrote

#

or =2^2 but 4 works too

#

Im pretty sure that is correct, nut i really don't know about the parabola

#

I don't have to find the directrix or the Focus

#

<@&286206848099549185>

drowsy ledge
#

Oh wait

#

0iq

#

I just have to work backwards

#

Thanks for helping me

#

, me

#

No problem

viral copper
#

Hi can someone tell me what i did wrong pls

willow bear
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@viral copper your numerator has higher degree than the denominator

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so to do a pfd you would need to do long division first

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i.e. express (x^3+2x^2-1)/(x^2+x-6) as the sum of a polynomial and a proper fraction

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where 'proper fraction' means a fraction where the degree of the top is strictly less than that of the bottom

viral copper
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tysm appreciate it

solemn vault
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can someone help me verify this problem?

jagged glade
viscid thistle
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how do you solve this by hand?

soft cargo
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That's equal to log2(12^2)+log2(5^3)-log2(15)-log2(150)

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which is equal to log2(12^2*5^3) - log2(15/150)

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which is equal to log2(10*(12^2 * 5^3))

viscid thistle
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Apparently not

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the answer comes out as 3 on my cas

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but that doesn't equal 3

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equating the question and your answer returns false

uncut mulch
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do you know your log laws?

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specifically stuff like power law, sum to product, difference to quotient

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(the other person messed up the order of operations)

viscid thistle
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yes

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have i gone wrong here?

raven kindle
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what is the formula of finding chord in a parabola?

willow bear
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there is no formula and you should not look for one

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or are you expected to do problems like this in under 10 seconds?

raven kindle
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I already graph the parabola

willow bear
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if you're able to find the focus of the parabola then i fail to see what could trouble you about this

raven kindle
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my problem is that I could not find the other endpoint of the chord

willow bear
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have you found the focus?

raven kindle
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yup

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V(0,0)
F(0,3)
D(0,-3)
Q1(6,3)
Q2(-6,3)

willow bear
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so have you found the equation of the chord?

raven kindle
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the other endpoint of the chord is (8,16/3)

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and i could not find the other endpoint

willow bear
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answer me

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have you found the equation of the chord

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yes or no

raven kindle
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no

willow bear
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okay why not

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it goes through (8, 16/3) and the focus.

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and it is a straight line

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why were you unable to find the equation of the chord?

raven kindle
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okay nevermind

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thanks for the help

willow bear
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that sounds like a thinly veiled "fuck off" to me

civic furnace
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How do I get a formula of a function from a partially filled table, i.e. (lhs is x, rhs is y) 0 = -2, 2 = 0, 3=5 4=9 7=12
Do I just guess or is there some method to it

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Function f assigns every natural number n the number of digits required to write it in decimal form, e.g. f(7285) = 4
Give all the arguments n < 3000 for which the following equality holds f(n+1) = f(n) +1

No idea how to do it

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Function g assigns every number x in [-5, 6] the smallest integer n such that 3n > x

What's the root of the function?
The answer given by the book is -3, but I think it's also -2 and -1

civic furnace
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@surreal crest

willow bear
willow bear
surreal crest
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You can use lagrange polynomial interpolation.

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And just hope

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That it's right

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(it won't be)

willow bear
surreal crest
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f is well defined though

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There's a function for it

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For the first one

willow bear
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well it's defined on {0, 2, 3, 4, 7} maybe

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but nowhere else

surreal crest
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Idk about the second one

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Can't think, all blood in my legs rn

civic furnace
surreal crest
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Also zoosmell pooplord is better than troll

willow bear
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C?

civic furnace
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it means Z

surreal crest
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Polish?

civic furnace
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yeah

willow bear
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so you are told that it is increasing.

civic furnace
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sometimes C is used instead of Z

surreal crest
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Z is zahlen

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German

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Why dont they use the standard

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C is complex

civic furnace
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C isn't used for Z anywhere beyond highschool

surreal crest
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Infuriating

civic furnace
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check Zs

willow bear
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no you don't guess it

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you are missing f(1), f(5) and f(6)

civic furnace
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oh right

willow bear
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and you're told the values of f at everything else