#precalculus

1 messages · Page 20 of 1

viscid thistle
#

I am modeling the population growth of the Netherlands, and what can I use to fit data into logistic and exponential growth models?

sinful halo
#

you can rewrite this as $2(\frac{ln(x)}{ln(2)})=x$

obsidian monolithBOT
sinful halo
#

ah, this is an intermediate step

exotic skiff
#

Can anyone please guide me;-;

arctic dragon
#

Can you explain how you got this please

willow skiff
#

you want to go to the calc channel

worn cape
charred fiber
#

I got a question. I had to determine if a equation would be even and odd on a graph by using f(-x) and -f(x) on a quiz. I got the answers right; however, she subtracted 1 point off of each question because when showing my work I didn't include f(-x) and -f(x) in my problem. So for example I wrote 2x+4 instead of f(-x) = 2x+4. She never told the class this. The answer she wanted was either odd or even so I just did the work and didn't bother labeling because I only needed to circle odd, even, or neither. But those points she subtracted off left me with a 19/22 on a test that I would have gotten a 100% on. Is this fair? Should I ask her about it or is it my fault?

jovial seal
charred fiber
#

okay thanks 👍

#

my friends who got a 100% on the quiz said that they just put that there out of habit and also didn't know you had to as well. And they all said I should talk to her about it.

viscid thistle
#

What are some great books that teach precalculus through real world applications like physics or engineering?

normal coral
remote mesa
#

its cause they take the 'calc' in precalc too far

warm oyster
#

then arent we allowed to ask help for integrals etc things here?

willow skiff
warm oyster
#

but the channel belongs in early university

#

so im confused

shadow summit
warm oyster
#

calculus is a part of high school wdym

#

derivatives, limits belongs to this channel right?, arent they

untold shuttle
hushed sphinx
# warm oyster calculus is a part of high school wdym

In the US, whose traditions inform the channel organization, calculus is commonly taught in the first year of university. Therefore the #calculus channel is located in the "early university" category. That doesn't mean one has to actually BE in university to use it. The categories are just a practical arrangement to avoid having all of the channels lumped together in one long list.

warm oyster
#

oh ok, thanks 👍🏼

untold shuttle
#

????????

#

i never knew that

#

interesting

hushed sphinx
#

Depends on which country/system you're in.

elfin matrix
#

calc can be taught at pretty much any level depending on the country and education system

elfin matrix
hushed sphinx
#

I'm led to believe it is not all that uncommon in the US to learn calculus in high school. They just tend to think of it as "particularly bright/interested students get to learn some university topics early".

#

Conversely, it is not uncommon to see basic calculus taught at European universities -- just billed as "remedial high-school mathematics for STEM students who followed a low-math track in high school".

#

So the actual differences on the ground might not be as profound as the overall generalizations suggest.

untold shuttle
# hushed sphinx Depends on which country/system you're in.

im a hong konger taking IB. Usually we math nerds get taught it early in 10th or 11th, but we also have it for 9th grade as a super-extension task. I am a freshman, but because of 🤓 , i've already learnt the equivalent of roughly 25-30% of calc 1

#

including me, there are 3 people in my maths class (higher level, rigour based, we call it "Pure maths") who know calc

#

i thought it was a high schooler subject

deep prism
#

hi

vagrant goblet
#

hi whats the log in base 1 of 1?

hushed sphinx
#

"Log in base 1" does't make sense.

thin roost
#

can anybody explain the rational root theorem and how syntetic/long divison for polynomials work

#

like why does the algorithm work

wet nest
#

Can anyone help me to solve this?

wet nest
viscid thistle
#

dawg is this multi variable calculus

twilit eagle
#

nah precalculus 💯

viscid thistle
valid parrot
#

Is there any limit
[ \lim_{x \to k} f,(x) = 0 :, \quad \lim_{x \to k} g,(x) = 0 :, ]
such that
[ \lim_{x \to k} {f,(x)}^{g,(x)} \neq 1]

obsidian monolithBOT
#

ταυταυ

valid parrot
#

I found one btw

thin roost
#

i havent been able to find any videos on the why though

#

ill keep searching

grave bear
#

anyone know why ap precalc is a thing now

smoky pendant
#

for these problems do you reflect first, translate left/right, then up/down?

#

for example, 37 would be reflect over x axis, then shift 1 right, and up 2

whole spruce
#

quick question is ratio of cotθ the same thing as finding the exact value?

viscid thistle
#

u by ratio u mean the ratio of the lengths of the triangle sides

#

then yeah

whole spruce
whole spruce
#

inverse of tangent

#

1/tan?

#

Not sure

worn cape
#

and how can you rewrite tangent then?

whole spruce
worn cape
#

There’s a special way you can rewrite tangent in terms of sine and cosine

#

and since cotangent is the reciprocal you can flip that

whole spruce
viscid thistle
whole spruce
viscid thistle
#

now why do you wanna confuse the lad

#

bruh

#

ok

worn cape
#

Can you put your work in here?

whole spruce
viscid thistle
#

derive what

#

that tan=sin/cos?

worn cape
viscid thistle
#

oh

#

ok

whole spruce
#

that’s basically what i did

viscid thistle
#

what

#

ig?

#

that works

worn cape
whole spruce
#

am I complicating myself?

viscid thistle
#

not that ur way is complicated but there's an easier way

whole spruce
worn cape
#

but the way we were thinking is by doing cot (theta) is cos/sin

#

then you sub in the value for sine and the pythagorean identity version of cosine

#

and plug in and simplify

#

your way is completely valid and probably less abstract anyways

whole spruce
#

If one of you guys can write it down for me, that’d be great

viscid thistle
worn cape
viscid thistle
#

u can understand the sin bit through sohcahtoa

whole spruce
#

secθ<0
can someone explain this to me?
i view it as when cosine is + or is it -?

#

The inverse

#

The negative

#

Sec=- ?

slim steppe
#

It's not the inverse

#

It's the reciprocal of cosine

whole spruce
#

not sure

slim steppe
#

😦

#

1/5

#

or .2

whole spruce
#

1/cos

#

This sign means “<“ greater then right?

#

So then cosine is greater then 0?

#

its the same question from above

#

i just want to make sure I understand it

#

Cause i guess on that sec part

#

all i want to know is
when sec < 0 is equal to +
when sec > 0 is equal to -
?

#

when putting it inside the quadrant

#

ok thanks

#

I havent learn that yet, but it’d come in handy soon. I appreciate the help

dry chasm
#

While finding max of function using derivative can we directly assume the point of Max the point we get after equating first derivative to 0 without checking the sign of second derivative ?

viscid thistle
#

Isn't it suppose to be 6x¹ not 9x² ??

warped plume
#

no

#

its simplified, not chain rule

viscid thistle
#

Then he just calculated the 3² so it became 9x² ?

dry chasm
slim steppe
#

Well, I believe the correct way of saying it would be "the negative reciprocal"

warped plume
cinder prairie
#

hi calculus here 😎

warm oyster
#

damn

wind flint
#

calclus is best type of calculus

#

fr

cinder prairie
#

ikr?

steady bear
warm oyster
steady bear
#

Lmfao

warm oyster
#

predicting

slim steppe
#

bravo to the people that have actually went into that field of research

summer mirage
#

Quick question: How do I verify this identity?

#

sinx/cosx (I just simplified if from tanx)

summer ruin
#

do something about left hand side

snow root
#

Hold on am I bugging or does the left simplify to -cosx

#

If u plug in pythagorean identity for 1

summer mirage
#

The original identity was:

summer mirage
summer ruin
#

what is your question?

#

why is there a second identity and which one are you asking about

snow root
summer mirage
#

nvm,

#

It is solved]

#

Someone just explained it to me

#

Thanks tho

snow root
#

Can u send solution I am curious

summer mirage
#

yeah

#

hol up one sex

#

sec*

#

NOT THE OTHER WORD

#

sec*

snow root
#

Lol

summer mirage
#

Original:

#

Result

snow root
#

Hmm

#

1+sinx-cos^2x becomes sin(1+ sinx)

#

Ok that makes sense

#

Thanks

summer mirage
#

you're welcome

summer mirage
#

Do I cancel out the 9/4 sec^2theta. Or do I simplify the radicand first?

summer ruin
#

there's nothing to cancel

white lion
summer mirage
#

I did

#

Thanks tho'

#

Much appreciated.

solar olive
viscid thistle
#

Why the answer here is -√3 not √3 ??

uncut mulch
#

you dropped the - sign from the previous line

#

which came from chain rule/derivative of
35 - 5sec(x)

#

also with the presence of differentiation, it's calc not pre-calc
please use the correct topic or claim your own channel

viscid thistle
cinder prairie
viscid thistle
shadow summit
obsidian monolithBOT
#

TheLord26

north sable
#

Is there a section for calculus bc I am taking AP calculus ab

crimson prism
#

uts probably grouped together

terse tiger
crimson prism
cinder prairie
whole spruce
#

when its csc(5pi/2) can i look at it as sin(5pi/2) ?

hushed sphinx
#

Both csc(5pi/2) and sin(5pi/2) happen to be 1, so they are the same -- but only for that mostly accidental reason.

whole spruce
#

how to i go from exact values to radians
example -> cos(1/2)
what would that be in radian form?

hushed sphinx
#

Huh. Do you mean the cosine of half a degree, and you want to write that half a degree in radian form?

whole spruce
hushed sphinx
#

Huh?

#

Did you mean arccos(1/2)?

whole spruce
#

maybe i wasnt clear with my question

#

my question says costheta=1/2

vapid plaza
open plank
#

trigonometry is fun !

restive carbon
#

Hello I need a little help with precal

#

How do you find the slope on a graph ?

glossy delta
#

Given 2 points

glossy delta
#

Difference in y/difference in x

dusty bear
#

can anyone teach me calculus

#

since, idk anything

glossy delta
#

What about calculus

dusty bear
#

.

#

tell me where i can stuy caluclus ( 0 money )

#

@visual trail

glossy delta
#

In your highschool probably

dusty bear
#

bruh

#

i in (

#

im in 9 th grade but i wanna learn calculus

gaunt carbon
#

can't really do it well without the foundational stuff

glossy delta
#

^

#

Calculus is 99% algebra

gaunt carbon
#

literally tbh

dusty bear
#

trignometry basic lvl

#

lol

gaunt carbon
#

have you done like. csc sec and cot stuff

dusty bear
#

yes

#

i k the basic identites

#

what grade are u in ?

gaunt carbon
#

I'm in 11th grade

dusty bear
#

W

gaunt carbon
#

when it comes to algebra how do you feel to that end

dusty bear
#

ik these many identites

#

not the below let part

dusty bear
gaunt carbon
#

okay cool

#

if I were you instead of looking at calculus i'd become more familiar with trigonometry
probably look at trigonometric equations, polar coordinates, and complex numbers just to get again a good base
they usually come in handy later
and then when it comes to algebra if you haven't done this stuff already I recommend getting very very comfortable with conic sections and piecewise functions along with inequalities
all those are really prep for calculus
if you want to dive straight in though, I would check out 3blue1brown's video on the subject and maybe see if you could do some on khan academy as they have fairly in-depth calculus resources

dusty bear
#

i have basic idea on complex nos

#

but thnx i really aapreciate

gaunt carbon
#

yeah of course

dusty bear
#

which country are u ?

gaunt carbon
#

from the US

dusty bear
#

oh ok

shadow summit
valid parrot
#

linear algebra in uni is very fun you'll see bleakkekw

shadow summit
valid parrot
#

yeah

#

xdd

gaunt carbon
#

linear algebra truly is iconic tbh

valid parrot
#

i love it

crimson prism
#

if u wanna learn p basic calc go up till chp ig 6?

#

after that its haevy integratation based

#

also make sure u can do basic math rly well cuz like it is very heavy algebra based when ur solving the stuff

#

imo u dont rly need precalc for calc

gaunt carbon
#

you dont need it necessarily but it does have its usefullness later down the line

plain frigate
#

Guys,would you mind some of you can help about that

willow skiff
warm spoke
inner moat
#

can someone help with composite functions

brisk adder
#

Can you show what you have so far?

hushed sphinx
#

They're plainly composed of f and g (and the addition and subtraction operations).

halcyon trout
#

Anyone can help me with this

heady elbow
#

help

halcyon trout
#
  1. ( \lim _{n \rightarrow \infty}\left(\frac{2 n^{-2}(n !)^{3}}{3(n-1) ! \cdot(n+1) ! \cdot(n-2) !}\right) = \lim _{n \rightarrow \infty}\left(\frac{2 n^{3}}{3(n+1)(n-2)}\right) = 0 )

  2. ( \lim _{n \rightarrow \infty}\left[2 n^{2}\left(\sqrt[3]{2 n^{3}-1}-\sqrt[2]{2 n^{3}+1}\right)\right] = \lim _{n \rightarrow \infty}\left[2 n^{2}\left((2n^3)^{1/3}-(2n^3)^{1/2}\right)\right] = -\infty )

  3. ( \lim _{n \rightarrow \infty}\left(\sqrt{n^{2}+5 n+3}+\sqrt{4 n^{2}+2 n-1}-3 n\right) = \lim _{n \rightarrow \infty}\left(n\sqrt{1+\frac{5}{n}+\frac{3}{n^2}}+2n\sqrt{1+\frac{1}{2n}-\frac{1}{4n^2}}-3 n\right) = n )

  4. ( \lim _{n \rightarrow \infty} \frac{\sqrt{n+2}-\sqrt{n-1}}{\sqrt{9 n^{2}+2}-3 n} = \lim _{n \rightarrow \infty} \frac{1}{3\sqrt{n}} = 0 )

  5. ( \lim _{n \rightarrow \infty}\left(\frac{1+3+\ldots+(2 n-1)}{n+3}-n\right) = \lim _{n \rightarrow \infty}\left(\frac{n^2}{n+3}-n\right) = \lim _{n \rightarrow \infty}\left(\frac{n(n-3)}{n+3}\right) = \infty )

  6. ( \lim _{n \rightarrow \infty} \frac{1+\frac{1}{2}+\frac{1}{3^{2}}+\ldots+\frac{1}{3^{n-1}}}{1+\frac{1}{5}+\frac{1}{5^{2}}+\ldots+\frac{1}{5^{n-1}}} = \frac{\frac{3}{2}}{\frac{5}{4}} = \frac{6}{5} )

  7. ( \lim _{n \rightarrow \infty} \frac{\sqrt{n}}{\sqrt{n+\sqrt{n+\sqrt{n}}}} = \lim _{n \rightarrow \infty} \frac{1}{\sqrt{1+\frac{1}{\sqrt{n}}}} = 1 )

  8. ( \lim _{n \rightarrow \infty} \frac{n \cdot \sin n}{n^{2}+1} = 0 )

  9. ( \lim _{n \rightarrow \infty}\left(\frac{\mathbf{1}}{\mathbf{1} \cdot 3}+\frac{\mathbf{1}}{2 \cdot 4}+\ldots+\frac{\mathbf{1}}{n \cdot(n+2)}\right) = \frac{1}{2} )

  10. ( \lim _{n \rightarrow \infty}\left[\left(1-\frac{1}{4}\right)\left(1-\frac{1}{9}\right) \ldots\left(1-\frac{1}{(n+1)^{2}}\right)\right] = \frac{2}{3} )

obsidian monolithBOT
halcyon trout
arctic magnet
#

Holy

halcyon trout
#

Can anybody help me with this

tropic bone
plain frigate
#

Folks in this graph problems ,we suppose to use vertical and horizontal asymptote or Someone have a idea ?

granite temple
plain frigate
gaunt carbon
whole spruce
#

for this equation can you cube a negative number?

hushed sphinx
#

Why wouldn't you be able to?

whole spruce
#

so you can cube a negative number?

gaunt carbon
#

yeah?

whole spruce
#

so when i cube it does it become -1? like how you would square root 1?

tender mist
#

I think I see what you're asking. Yeah, it's possible to do that. All odd roots are able to be done on positive or negative numbers. It's only even roots that are bound to positive numbers

whole spruce
hushed sphinx
#

Umm, what is the "it" you're cubing to get that?

whole spruce
hushed sphinx
#

Cubing (each side of) that gives 512cos^9(theta) = -1.

whole spruce
tender mist
#

You isolate by doing the opposite operation. So dividing by 8, and cube rooting

#

Which is why I mentioned the odd and even root thing. Thankfully since it is an odd root, you can root a negative

warm spoke
#

@exotic barn ok so i noticed that when you have a zero in the denominator thats not in the numerator of a rational function thats a vertical asymptote and if theres a shared zero in the numerator and denominator then its a hole but is it possible to have a jump

exotic barn
warm spoke
exotic barn
#

haha thanks

warm spoke
#

i cant think of when a rational function would have a jump

#

im getting the vibes

#

that it has something to do

#

with limits

#

and rates of change

#

but vibes only take you so far

hushed sphinx
#

Rational functions don't jump, but they can have vertical asymptotes even where the numerator is 0 -- consider for example x/x².

#

(Silly example, but the instances of this are generally silly in the same way).

warm spoke
#

why cant they jump though

#

oh wait

#

rational functions are just polynomials

#

nevermind

#

i mean any function with a numerator and denominator part

hushed sphinx
#

Hmm, I don't have an elementary argument for that ready.

warm spoke
hushed sphinx
#

Well, in that case |x| / x does jump.

warm spoke
#

other than by just looking at it

hushed sphinx
#

I'm not sure how to do anything with a graph that's not looking at it ...

warm spoke
#

moreover how would you describe them like would you describe them by their left and right point and which point is defined

warm spoke
#

actually

#

idk what i mean

dusky current
#

If f(x) = x^3-5x^2-4x
and g(x) = 2f(x) + q
Find all values of q if g(x) has exactly one x-intercept

half vector
#

hello guys, u discuss here about the basics of calculus?

stable vessel
#

Can someone help me

#

What this notation means?

warm oyster
stable vessel
warm oyster
stable vessel
#

The red one

warm oyster
#

oh okay so yea it is the union of -infinite to -3(not included) and 0(included) to + infinite

#

and the x in blue is thier final result, that is thier intersection

stable vessel
oblique sapphire
#

you mean $\cup$ and $\cap$ right

obsidian monolithBOT
#

RottenGold

oblique sapphire
#

$\cup$ is called the "union" of 2 sets, it combines 2 set. $\cap$ is the "intersection" of 2 sets, it finds the overlapping elements of 2 sets

obsidian monolithBOT
#

RottenGold

stable vessel
#

I missread the question

warm oyster
#

lmao that happens

stable vessel
#

Because of |x| ≤ 3

#

A thing I hate about learning maths is sometimes having to spend more than half an hour on a single page tl understand it, but it is fun

unique path
lunar cairn
#

hello everyone i have a question , im 10 grade right now and i want to start learning precalc and after calculus by my self but i dont know where can i start can any one tell me the roadmap or something like that

viscid thistle
#

That's where I studied all my base of calculus from

lunar cairn
#

alright thanks let me search about it

digital mirage
#

is this not a dirichlet function ?

vast quartz
#

I'm studying my precalc with the openstax book

viscid thistle
#

The calculus part such as derivitives and intergrals are easy

#

Trignometry is also a hard chapter

lunar cairn
#

so which one i have to start first and also i want to take ap calc ab at next year

viscid thistle
#

I sent you in dms

#

The book I used

lunar cairn
#

ok i got it

#

thanks

viscid thistle
#

Just follow that

#

That was my grade 9 and 10 book

tender mist
#

Just curious what I should be finding with a question like this. I understand the end goal, and generally what it is I'm supposed to do, but I don't really know how to start it

I'm just self-learning, and I'm not in an official course, so I'm just a bit confused. My school back then never really covered trig with functions, so I'm inexperienced with this type of situation

#

I don't need the answer, just want to know what processes I should be applying to that question

gentle kettle
#

so just xor?

#

symmetric difference

strong epoch
#

Does anyone know how to simplify this

warm oyster
#

idk think it can be simplified any further but the only thing i can make sense of is multiplying both side by 1-sin theta

#

@strong epoch

strong epoch
#

I tried that

#

Got that bottom would become cos^2x

#

Then wouldn’t it be -cossin/cos

#

I thought it was -sinx but it was marked wrong

uncut mulch
#

how are you getting
-cos(x)sin(x)/cos(x)

strong epoch
strong epoch
#

N

uncut mulch
#

cos/cos^2 does simplify to 1/cos,
but you don't just have cos/cos^2

strong epoch
#

Can I just simplify it like that?

uncut mulch
#

no

strong epoch
#

Oh

#

Why

uncut mulch
#

fractions get simplified from cancellation of a common factor
and not erasure of expressions that happen to appear

strong epoch
#

Oh yea

#

So I can’t do that

#

Fruck

#

I don’t know how I would simplify it further

uncut mulch
#

here you'd want to factorise the numerator
or not have expanded in the first place

strong epoch
#

So -cos(sin)

uncut mulch
#

no

strong epoch
#

1-

#

?

uncut mulch
#

no

strong epoch
#

What is it cos( 1-sin)

uncut mulch
#

yeh

#

that'd be the unexpanded numerator

strong epoch
#

Cos( 1-sin)/cos^2x

uncut mulch
#

$\frac{\cos(x)(1-\sin(x))}{\cos^2(x)}$

obsidian monolithBOT
#

ℝαμΩℕωⅤ

uncut mulch
#

now that it's clear that cos(x) is a factor of both the numerator and denominator, you can cancel

strong epoch
#

1-sin/cos

#

Thanks

fast plover
#

not really sure how to finish this question

#

this is my working out, but i dont know how to eliminate the value for a

radiant kite
fringe quest
#

Then we know that sin-1x = pi/2-cos-1x

#

Then just euqate the angles for x

willow skiff
#

alternatively, take the sin/cosine of both sides

#

the identities can be found from a right triangle

shadow creek
#

anyone have any tips for gauss elimination

spark moat
#

its gaussian eliminqtion without fractions

#

and then convert to gauss-jordan

shadow creek
#

ik how to do it

#

i just want tips

#

on what should i start with and what not

spark moat
#

well its a type of gaussian elimination j without fractions

shadow creek
#

it's standard gaus

spark moat
#

no bc this way avoids fractions

grave crag
#

Can anyone explain how to solve this problem? I posted the solution as well.

whole spruce
#

How do i find this point? Where the arrow is pointing
im looking for the phase shift of the function

summer ruin
#

solve f(x) = 0

potent gull
#

I urgently need someone who knows Calculus

frigid trout
shadow summit
obsidian monolithBOT
#

TheLord26

open badger
#

what is

#

2cm+4cm(4+1)

willow skiff
shadow summit
whole spruce
shadow summit
whole spruce
#

the only values im given is the numbers that are marked on the graph

shadow summit
obsidian monolithBOT
#

TheLord26

shadow summit
fervent crag
#

What do I need to know before I venture into calculus?

whole spruce
shadow summit
#

Basically what I did was counted how big each of those units are, which was pi/24, from there it was pretty easy.

worn cove
#

and a good amount of algebra

shadow summit
#

Algebra

#

Calculus is 90% algebra

worn cove
#

yeahh

#

i gotta step up my algebra game more ngl

#

im not in college still but next semester, i'll be taking up basic calculus

shadow summit
#

Also if you’ve done complex numbers before those are pretty annoying to divide.

arctic sundial
#

I don’t understand why it’s not the thing I circled on the top (not the answer)

#

Isn’t converting it to a different time rate make it like that?

shadow summit
#

What you have done is multiplied 12 (the number of times the price increase per year) by t/12, which cancel out, thus leaving you with just t.

#

And because the price doesn’t increase only once per year this is wrong.

arctic sundial
#

Omg Ty so much

fervent crag
#

Trig needs more work

tender mist
#

For a bit of background context, I'm technically not in school right now, and haven't been for a little while, so while I have taken pre-calculus before, I'm a bit rusty. I understand what the question is asking me to do, but I'm not sure how I'm supposed to go about doing it. Can anyone tell me what formulas or rules I'm supposed to use on this one? Not necessarily asking for the answer (you can provide if you want, I don't mind), I'm just curious about the process itself

elder bane
#

Help, what are the rules for integrals

warped cipher
obsidian monolithBOT
#

Akira (fumo)

warped cipher
left zodiac
#

i was doing random stuff with exponents when i found smth weird
so i have x^x right, and it's defined on [0;+infinity[ since apparently 0^0 is 1
but as far as i know you can write x^x as exp(xln(x)) which cannot be defined on 0
my question is where did i go wrong, is there something i didn't do correctly when i rewrote x^x ?

summer ruin
#

because 0^0 is not 1, it's undefined

tender mist
left zodiac
#

thanks

summer ruin
shadow summit
left zodiac
#

i guess i'm just gonna

gentle sapphire
#

Guys, what algebra and trigonometry do i need specifically to be able to understand calculus?

shadow summit
left zodiac
#

idk about trigonometry

#

but probably all of it too

shadow summit
gentle sapphire
shadow summit
#

Google “what does a pre calculus course have”

summer ruin
#

everything that's part of the school algebra and trig course

left zodiac
shadow summit
#

Once again, calculus is 90% algebra

tender mist
# summer ruin draw the picture

I generally know what it looks like, the problem is I'm not sure about the equations. I don't think I'm supposed to find the answer with a graphical solution

summer ruin
#

it's not like the exercise explicitly forbids you to use valid mathematical tools?

tender mist
#

Of course, but I'm pretty sure there's an algebraic solution, no?

summer ruin
#

once you draw the picture the equations will be obvious

#

I mean if you can't even visualize the problem in your head and what it's asking, then it's not clear how you would come up with algebraic solution

kind topaz
#

taylor series

tender mist
#

I wouldn't have a problem with the question if it was asking for just a function period. But it's asking about the function of the slope. I'm not sure how to create the final answer based off of just that variable

summer ruin
#

try to figure out the slope of the line joining P with the origin first

tender mist
#

And is a graph required to do that? Like I can't do it any other way?

summer ruin
#

depends on how well you understand what the problem is asking

#

you already given the information what the coordinates of P are technically

#

in the problem statement

tender mist
#

The problem is, I don't know how to find the coordinates. I was trying to find them earlier, but I must've been doing it wrong. That's why my original question was asking what equations or rules I have to use to find it. I've done a problem like this before, but it was years ago, and I'm just rusty

summer ruin
#

suppose P has coordinates (p_1, p_2) and you're given that P lies on the graph of f(x) = sqrt(x)

#

what can you say about coordinates of P now?

#

and it being in the first quadrant

shadow summit
#

Try graphing stuff on Desmos.

tender mist
#

Am I just misunderstanding the question?

shadow summit
#

What do you think the question is asking?

tender mist
#

I thought it was asking what point on the unit circle had the same point as a point on the line of sqrt(x). I know, I know, the question didn't explicitly mention it, but I assumed because of the word "quadrant", I think that threw me off

Am I only worrying about the sqrt(x)?

shadow summit
tender mist
#

So any point, in general?

#

As long as it's in that quadrant, on that line?

shadow summit
#

Yes

tender mist
#

Okay, thanks, that simplifies what rubbish I was trying to assume it meant, lol

#

That should be good, I think I know what to do now

shadow summit
#

The first quadrant is whenever the x and y values of a point are both positive (in this case every point you are working with should lie in the quadrant).

tender mist
#

Right. I just never heard that term outside of trig when I used to go to high school, so I always treated it as a "trig term"

shadow summit
#

Understandable.

shadow summit
tender mist
#

Aighty thanks. I should be fine for now. I'm actually not looking at a pre-calculus textbook, I'm doing calc, but I'm in the first chapter which consists of pre-calc stuff, so I'll probably stick around here for now

#

Actually one more thing. What is meant by a "natural domain"? I don't think that term ever showed up where I went to school. I know about domain, but I don't know what a natural domain is

shadow summit
tender mist
#

So depending on the question, they can mean exactly the same thing, if there wasn't a domain restriction, since natural domain has no restrictions except what the function itself has. Gotcha

#

I figured that's what it was, but I was confused, lol

shadow summit
#

My teacher absolutely hates a certain textbook because of how it says stuff.

tender mist
#

Yeahh, I think my schools always had their own sources, so I'm not familiar with math textbooks in general

shadow summit
#

I got used to it cuz I used 3 different text books.

tender mist
#

Dang, nice. Right now I'm using Thomas' Calculus book. I know this covers like 3 courses in 1 book, but it should still be helpful anyway

shadow summit
#

Nice, might check it out.

tender mist
#

Far as I know, it covers calc 1 to 3

#

Or mostly

#

Over 1000 pages

shadow summit
#

Well, I’ve got some time to kill later today. I’ll get a start on it so I don’t feel lazy.

whole spruce
#

can someone help me find the phase shift of this cosine graph

unkempt drift
#

can any one solve this

brisk adder
warm oyster
obsidian monolithBOT
#

ഴajat

warm oyster
#

and then put the limits

unkempt drift
#

ok thanks

whole spruce
delicate bloom
scenic coral
#

$\text{power rule}\ \int x^n dx = \frac{1}{n}x^{n+1} + C\ \text{and then use fundamental theorem of calculus} \ \int_{a}^{b} f(x)dx = F(b) - F(a) \ \text{where b > a and F(x) is the antiderivative of f(x)}$

obsidian monolithBOT
#

someone1010

stuck harbor
#

are the vertical asymptotes 4 and -3

#

it says it’s only 4 on mathway

#

but i think i’m supposed to plug in -3 and 4 on the number to find the limits

scenic coral
#

If the binomial cancels in numerator and denominator you get a point discontinuity rather than a vertical asymptote

#

Ex: (x+1)x/(x+1)

#

,w graph (x+1)x/(x+1)

obsidian monolithBOT
scenic coral
#

notice that there is no asymptote

stuck harbor
#

yes

#

why though

scenic coral
#

Well, a/a = 1

stuck harbor
#

yeah

scenic coral
#

It doesn't go to inf bc it cancels

stuck harbor
#

how do i know that it is only 4

#

is because the x+3 already cancels out

scenic coral
#

Not sure how to rigorously prove, but 4 doesn't cancels so it makes an asymptote, though that's not a satisfying explaination

stuck harbor
#

ok

stuck harbor
scenic coral
stuck harbor
#

ok thx

#

on the number line would it also just be testing the 3.9 and 4.1

untold adder
#

Is this the notation of a primitive function ?

summer ruin
#

it's second derivative

untold adder
#

Thanks.

warm oyster
lunar creek
#

Total number of calls:
We know that the average number of calls per hour is 30. Therefore, the total number of calls in 150 hours follows a Poisson distribution with parameter (\lambda = 30 \times 150).
Number of men in calls:
Since 60% of the calls are made by men, we can consider the number of men in 150 calls as a binomial random variable with parameters (n = 150) and (p = 0.6).
Waiting time for reward:
The time between calls follows an exponential distribution with parameter (\lambda = 1/30) (since there are on average 30 calls per hour). So, the total time elapsed before the 100th call arrives is a sum of 100 exponential random variables.
For calculate these probabilities, we use the approximate Poisson distribution for the sum of independent random variables. The Poisson distribution can be used when the number of events is large, and the probability of success for each event is small.
In detail, you can use the Poisson distribution approximation for a binomial random variable when the number of trials (n) is large and the probability of success (p) is small.
For the first point, you want to find the probability of having at most 75 men in 150 calls, we can use the binomial distribution.
For the second point, we want to find the probability that the waiting time for the hundredth call is at least 3 hours, we can use the Poisson distribution.
@viscid thistle

obsidian monolithBOT
#

☆⃞゙۪ ᪤hiִgh࣪nᧉ͟s̲s: 🫶🏻 𝖨𝘇𝗓𝕪 ܲ 𖧪

lunar creek
#

[ P(X \leq k) = \sum_{i=0}^{k} \binom{n}{i} p^i (1-p)^{n-i} ]

  • ( n = 150 ) (total number of calls)
  • ( p = 0.6 ) (probability of a call being made by a man)
  • ( k = 75 ) (maximum number of men)
    Calculate is
    [ P(X \leq 75) = \sum_{i=0}^{75} \binom{150}{i} (0.6)^i (0.4)^{150-i} ]
    For the second point, you use the Poisson distribution to calculate the probability that the waiting time for the hundredth call is at least 3 hours. The formula is:
    [ P(T \geq 3) = 1 - P(T < 3) ]
  • ( \lambda = 1/30 ) (rate of calls per hour)
  • ( T ) is the sum of 100 exponential random variables with parameter ( \lambda )
    Calculate is
    [ P(T < 3) = \sum_{i=0}^{299} \frac{(1/30)^i e^{-1/30}}{i!} ]
    In the end:
    [ P(T \geq 3) = 1 - P(T < 3) ]
obsidian monolithBOT
#

☆⃞゙۪ ᪤hiִgh࣪nᧉ͟s̲s: 🫶🏻 𝖨𝘇𝗓𝕪 ܲ 𖧪

lunar creek
#

@viscid thistle @wanton thicket

#

Oh sorry I tag you accidentally Priuz

viscid thistle
lunar creek
#

Np

viscid thistle
lunar creek
#

You can use those methods:
• Method of Moments:
The method of moments uses sample moments to estimate the parameters of a distribution. In the case of an exponential distribution like this one, the first sample moment is equal to the expected value of the distribution. So, we need to equate the first sample moment to the first theoretical moment. For the exponential distribution, the first theoretical moment is ( \frac{1}{a} ).
Calculate the first sample moment (( \bar{X} )) and solve for ( a ):
[ \bar{X} = \frac{1}{a} ]
[ a = \frac{1}{\bar{X}} ]

• Maximum Likelihood Method (ML):
The maximum likelihood method finds the value of the parameter that maximizes the likelihood function. For the exponential distribution, the likelihood function is given by:
[ L(a) = \prod_{i=1}^{n} a^2x_i e^{-ax_i} ]
It's often more convenient to work with the logarithm of the likelihood function (log-likelihood):
[ \ln L(a) = \sum_{i=1}^{n} [2\ln(a) + \ln(x_i) - ax_i] ]
Take the derivative with respect to ( a ) and set it equal to zero to find the value that maximizes the log-likelihood.

obsidian monolithBOT
#

☆⃞゙۪ ᪤hiִgh࣪nᧉ͟s̲s: 🫶🏻 𝖨𝘇𝗓𝕪 ܲ 𖧪

warped cipher
#

How's this precalc

viscid thistle
#

technically 1+1=2, is pre calc

warped cipher
#

read the channel's description

#

not that basically

viscid thistle
shadow creek
#

How do I set this up I can't figure it out

shadow creek
#

<@&286206848099549185>

candid gale
#

matrices- my enemy-

shadow creek
#

Can u help me please

#

I tried already but I don't know if it's right

shadow creek
#

What'd i do wrong

shadow creek
#

<@&286206848099549185>

shadow summit
# shadow creek

what are you plugging into your calculator? and what is the problem, is it the negative? perhaps one of your assumptions is wrong.

blissful pier
#

can anybody help me with understanding the basics of transformations, translations, and dilations of a linear function?

solemn shore
#

Use desmos

#

When 2X replaces X, less of a value is needed to replace Y value

#

Hence graph is factor of 1/2 along X axis

lapis sable
#

bro

#

rotate graph

shadow summit
proper zodiac
#

what are the cosh and sinh functions for, i know they exist but i’ve never seen them be used

wraith hawk
#

<@&286206848099549185>

#

Idk were to start with that

sinful moth
#

Halloo

#

How do you convert to general equation an ellipse thats equal to 0.5 not 1

summer ruin
#

multiply by 2?

#

if you meant to say equal to 1 and not 0.5

sinful moth
#

It doesnt workk

#

It shows different answer

#

x^2/(3sqrt(2)/2)^2 + (y + 21/5)^2/(3sqrt(2))^2 = 1

#

,help

obsidian monolithBOT
#

A brief description and guide on how to use me was sent to your DMs!
Please use ,list to see a list of all my commands, and ,help cmd to get detailed help on a command!

sinful moth
#

x^2/9+(y+4.2)^2/36=0.5

odd cloak
#

HELP Please

viscid thistle
odd cloak
#

the answer

#

;-;

viscid thistle
odd cloak
#

how

viscid thistle
#

n=7 too

#

n=11 too

odd cloak
#

;-;

#

depression

viscid thistle
#

n=15 too

#

ok

odd cloak
#

brains not braining

viscid thistle
#

n=19

#

n=23,27,31

#

ok done

#

idk why my butt is itching and i see the form 2^(3n)-3^n being divisible by 5

odd cloak
#

finding n wasnt the question

#

;-;

viscid thistle
#

sorry i am bit drunk today

#

i scratched my butt and for n=3+2k for k>=2 and k=0 agrees

kindred egret
#

Is anyone good at logarithms and exponentials?

shadow summit
# kindred egret Is anyone good at logarithms and exponentials?

Don’t ask a question like that. Just post the question you are resale trying to ask. Otherwise you will probably not get a response, and even if you do get a response you will have to follow up with another response to ask the question you initially wanted answered.

kindred egret
#

My apologies I have it posted I've just been patiently waiting

shadow summit
kindred egret
#

It's in the channel help 37

shadow summit
kindred egret
real cloud
#

can anybody help me

shadow summit
#

i swear, people just be asking for help instead of just asking the question.

real cloud
#

the part below it is what i got so far

shadow summit
#

are you aware of exact value triangles?

real cloud
shadow summit
real cloud
shadow summit
#

arctan(1/sqrt(3))=60 degrees.

#

x+135=60

#

x=60-135

#

x=-75

real cloud
#

are there any more answers or is it just -75

shadow summit
#

if it didnt ask for anymore solutions than you dont need any more.

real cloud
shadow summit
#

Not that I've heard of before.

shadow summit
#

They have exact values for the side lengths of triangles with interiors 45-45-90 and 30-60-90

#

i said exact value triangles.

#

huh, ive never heard of them being refered to as anything different, neither in text books, youtube videos or from teachers.

#

they arent really special, other than the fact that they have some of the most commonly used angles in them, and easy to represent side lengths.

#

Well all triangles have constant proportional sides.

#

take a right angle triangle with interior angles 15 and 75.

#

Set one of the side lengths equal to 1.

#

Solve for the remaining sides.

#

bam, proportional triangle.

#

What makes it proportional then?

#

yes, the triangle i have just created has all 3 sides being constants.

#

you do know what a constant is, right?

#

I made them the constant, therefor anything that shares the same angles will be proportional to the triangle i made.

#

They just have commonly used angles.

real cloud
#

tanx/secx simplified is sin x right

shadow summit
#

Yes

real cloud
#

Did I do this right

#

1 is the answer I got

kindred egret
#

I have a question: what are all the rules for logarithms and exponentials?

shadow summit
kindred egret
# shadow summit

Thank you, and which one would be the one you mentioned before? It was like a^log_a(x)=x

shadow summit
#

those arent all the log laws, but you should be able to do all questions using them.

kindred egret
#

Oh

shadow summit
#

here are a few more

kindred egret
#

Thank you

jolly harbor
shadow summit
jolly harbor
shadow summit
#

oh

#

im too tired to realise

#

dammit

#

i should have picked up on it, i love those kinds of jokes.

severe musk
#

how does one do these 😭

#

anybody here 😭

shadow summit
kindred egret
#

With systems of linear equations, what do you do when you get 0 = 0?

shadow summit
#

Try dividing the entire equation by a constant (hint:||3||)

kindred egret
shadow summit
kindred egret
#

I'm trying to find x,y,z

#

At this stage I would find out what x was but it becomes zero?

#

The calculator says I get
z=z
x=0-3z
y=6+z

#

But idk how

shadow summit
#

I don’t have a piece of paper on me rn, but start by doing equation 2-3(equation 3)

kindred egret
#

That gets me 0 = 0 I've tried

shadow summit
#

Do you know how to calculate where two lines meet?

kindred egret
shadow summit
shadow summit
# kindred egret Huh

Because if you focus on eq2 and eq3 by them selves, it is the same process for finding the values of y and z.

kindred egret
#

I get -y+z=-6

#

What i do with this

shadow summit
#

Then add the second and third equations together

kindred egret
#

That make zero?

shadow summit
#

Wait

#

I’m getting confused with something else

kindred egret
#

-3y+3z = -18
3y -3z = 18

#

0=0

shadow summit
#

Lemme just go do this on paper rq

kindred egret
#

Okay

#

Appreciate it

#

Considering one of the equations I got was x+3z=0, and the calculator says x is supposed to be 0-3z, it looks to me I'm supposed to get x by itself? But why

#

And how does z=z

shadow summit
#

Does this question come from a textbook?

kindred egret
#

Nope

shadow summit
#

So you created it?

kindred egret
#

No

shadow summit
#

Where’s this question from then?

kindred egret
#

It's a practice question generated from a professor

shadow summit
#

Uhhh

kindred egret
#

On Cengage I think it called

#

I can just put my help in a help channel

shadow summit
#

Maybe don’t trust that website.

#

It’s not possible.

kindred egret
#

But the calculator provides answer

shadow summit
#

What does calculator give you?

kindred egret
#

X = 0-3z
Y = 6 +z
Z = z

shadow summit
#

Wait

kindred egret
#

Ok

shadow summit
#

You’ve got 5 equations?

kindred egret
#

I made the next 4 and 5

shadow summit
#

Huh

kindred egret
#

3 were the question part

shadow summit
#

Are you trying to find z?

kindred egret
#

I'm trying to find x,y, and z

shadow summit
#

Yeah you can’t find z.

#

It’s impossible.

kindred egret
#

Yeah but what is the reason we write the answers like that

shadow summit
#

When I say “find z”, I mean like, it’s value (4, 19, 3.14, ect)

#

And if the calculator just says z=z, that means it’s impossible.

kindred egret
#

I see so since I got 0 = 0 it's impossible to find z and we have to write x and y in a different way

#

?

#

I think it's like you have to write x and y in relation to z

shadow summit
#

Put it this way, it’s like trying to the intersection point of two lines, but the they are the same line. So there is no single intersection point.

kindred egret
#

Yeah

shadow summit
#

That means the value of z does not exist.

kindred egret
#

What abt x and y

shadow summit
#

Well considering how we can’t solve for x or y without using z, it means that they are also impossible to find.

kindred egret
#

Oh

shadow summit
#

This happens because eq2 and eq3 are just the same equation.

kindred egret
#

but the calculator gave an answer?

shadow summit
#

No

kindred egret
#

No?

shadow summit
#

I used a calculator to check if there were any solutions and it basically just said it impossible.

kindred egret
#

Is my calculator wrong or smt I'm confused

shadow summit
#

Well it tells you x=-3z, and because there is no value for z it is impossible.

kindred egret
#

Oh I got it right

#

Problem solved

#

Thanks mate

willow skiff
#

the two roots can be the same

#

you're missing the part "counted with multiplicity"

#

so (x - 0)^2 tells us that x = 0 is a root with multiplicity 2

solemn notch
#

Does anyone have a roadmap or website I can follow

#

To learn pre calc and calc

#

Properly simply and correctly

#

Without confusing shoot

#

Like excsersises and stuff toowebsute

#

Too website*

zenith vapor
#

Help me pls

viscid thistle
#

OMG I thought I got banned for no reason.

shadow summit
clever dock
#

Someone give me any clue about what to do please. I don't even know where to start lmao.
The exercise asks to develop (1+n)^n with Newton's binomial and derivate the result of that in order to prove those identities.
Any clue would be very helpful

light forge
clever dock
#

I probably have made an error, but idk where

#

the other stuff I have are just random calculations in case I came up with sth, but that led me to nowhere

shadow summit
#

the original question starts with k=1, not k=0.

shadow summit
clever dock
clever dock
shadow summit
shadow summit
#

Anyways, I can’t help rn, I’m on my phone. I would’ve helped earlier though but its 12am now.

clever dock
#

I'm not sure but I think it supposes that it has been already demonstrated

clever dock
viscid thistle
#

ni

#

ce

whole void
#

but if find f(0)

#

u gotta evaluate 1/2 + 2/4 + 3/8 + 4/16 + …

#

which is two and there’s only more choice that matches up to this

grim maple
#

aankho se tune ye kya keh diya

#

dil ye deewana dhadakne laga

viscid thistle
#

How do you draw this?

#

I get an absurd number

shadow summit
#

Because you can jus make a table of a points that lie along the graph.

#

If that’s the level you are at

viscid thistle
#

basically The height of a tree in centimeters t years after it was planted, is given with the function shown

#

Then I need to determine grapgically the momentary growth rate after 10 years

viscid thistle
shadow summit
#

Honestly, I forgot how to do this without derivatives.

#

So if you are at the level where you can use derivatives and set the equal to 0, just use the first derivative to find the turning points, the second derivative to find the inflection point, and then just plug all those bales back into h(t).

#

But if your not at that point, idk.

viscid thistle
#

and there goes my help

#

I’ve tried deriving

shadow summit
#

Sorry mate

viscid thistle
#

this midterm went HORRIBLE

#

I’m so far behind it’s outrageous

viscid thistle
shadow summit
#

$h’(t)=-\frac{1}{10}t^{2}+5t$

obsidian monolithBOT
#

TheLord26

viscid thistle
#

Wha…

#

How did it come to that conclusion?

shadow summit
#

Set h’(t)=0 to find the x value for the turning points.

viscid thistle
#

oh God…

shadow summit
viscid thistle
#

I’m so tired rn

shadow summit
viscid thistle
#

Yes but you’re an undergraduate or a graduate 😂

#

a math major perhaps

#

I’m a preuni student

shadow summit
#

Don’t have school rn.

viscid thistle
#

Sleep!!!

#

Are you trying to hallucinate?

shadow summit
#

Well I can’t sleep now, it’s 6:17am

shadow summit
#

Not fun.

tranquil gull
#

What are you studying

shadow summit
#

Anyways I’m going I don’t have the mental strength for math rn.

viscid thistle
#

and physics

tranquil gull
#

Not new actually

tender questBOT
#

The purpose of this server is to help you learn, not to hand out answers. Do not ask someone to give you the answer directly.

untold adder
#

Use this property, and you'll find the answer.

restive carbon
#

whats good to study for a pre cal test ?

uncut mulch
#

algebra, functions, geo, trig, exponents, logs

near viper
#

can someone explain?

willow skiff
near viper
hushed sphinx
#

Compute the first few terms by hand -- do you see a pattern?

near viper
#

grows by 2n

willow skiff
near viper
#

right:

willow skiff
#

stop guessing

willow skiff
near viper
#

(1110)2^n-1 -1000

willow skiff
near viper
willow skiff
#

yes

near viper
#

then 1400

willow skiff
near viper
#

cuz only 100 doubles i think

willow skiff
#

mb

#

yeah

#

and then one more time to see the pattern?

near viper
#

1800

#

thanks alot btw

willow skiff
#

yeah nw

#

thank Tropo as well

viscid thistle
#

yo

#

can someone help me with precalc?

tropic coyote
#

what is it

#

theres a 50% chance ill be able to help

viscid thistle
#

ok

#

so it has to do with derivatives

#

which I don't have a problem with

#

the problem is the fricken equation

#

that has a cube and a square

#

with a fraction

tropic coyote
#

alright can i look

viscid thistle
#

i'll just show you here

tropic coyote
#

maybe i can help

viscid thistle
tropic coyote
#

oh that

viscid thistle
#

t is 10

tropic coyote
#

so what are you meant to do with it

#

set t=10?

viscid thistle
#

I get 216.666, but I can't derive it cuz the factor is hard

viscid thistle
tropic coyote
#

oh

#

just find derivative and set t=10

#

wait let me solve it first so i can help

#

will take like 2 minutes

viscid thistle
#

I did that, but no avail

viscid thistle
tropic coyote
#

nah
lim
h->0

viscid thistle
#

that's the limit value of deriving for growth rate

viscid thistle
tropic coyote
#

i mean you could say so

viscid thistle
#

wait...

tropic coyote
#

but i would like to keep the 2 variables separate

#

so they dont get mixed up

viscid thistle
#

t is x in this case, and I wanna find the growth rate at x = 10

tropic coyote
#

yes

viscid thistle
#

so where the heck am I making an error?

tropic coyote
#

it isnt h

#

can i see your work

viscid thistle
#

alright

#

but I've done multiple pages of it

#

lol

tropic coyote
#

i got 40 as value

viscid thistle
#

HOW?

tropic coyote
#

wait let me graph it to see if im right

viscid thistle
#

That's the correct answer but i couldn't come to that conclusion

tropic coyote
#

oh

#

alright so you did it with limits right

viscid thistle
#

yes

#

so wait

#

I seriously don't understand, did I mix up the wrong variables?

tropic coyote
#

i mean if you thought of t as h then

#

theres a signifcant chance of it

#

sorry

viscid thistle
#

I wrote

lim
t--> 0

#

was that wrong?

tropic coyote
#

yeah

viscid thistle
#

💀

tropic coyote
#

t is supposed to be what youre inputting into the derivative

#

not the difference thing in the derivative

viscid thistle
#

wdym

tropic coyote
#

like

viscid thistle
#

Ohhh

#

I see

tropic coyote
#

oh i was about to rewrite

viscid thistle
#

I wrote delta T, as in the change in T

#

but it's not delta

#

it's just t

#

t = 10

tropic coyote
#

yes

viscid thistle
#

man...

tropic coyote
#

and you have to use another variable as variable -> 0

viscid thistle
#

yes I have to use 10

#

as t reaches 10, y reaches 40

tropic coyote
#

nah you dont have to pull a limit trick