#precalculus
1 messages · Page 4 of 1
$$\sum_{a=1}^{4} \sum_{b=1}^{4} \sum_{c=1}^{4} max(a, b, c)$$
WhatIsSpin
I'm not sure how to go about solving this
I understand I'll get a lot of 3d points that will make a cube (1, 1, 1) (1, 1, 2) (1, 2, 1) up to (4, 4, 4)
And I think I need to add all those values up (1+1+1+1+1+2+1+2+1, etc.), but I'm not sure how to do that efficiently without manually doing it
4 - max(a,b,c) =
3 if all of a, b, c is 1
2 if otherwise a, b, c, is all 1 or 2
1 if otherwise a, b, c is all 1 or 2 or 3
0 if otherwise (a, b, c is all 1 or 2 or 3 or 4)
= (1 if a, b, c is all 1 or 2 or 3, 0 otherwise) + (1 if a, b, c is all 1 or 2, 0 otherwise) + (1 if a, b, c is all 1, 0 otherwise)
so add up the sum of each of these terms and subtract the overall sum from 64 x 4
answer should be ||64 * 4 - (3^3 + 2^3 + 1^3) = 220||
@oblique gazelle
Ah ok, that makes sense
And if it was a double integral from 1 to 6 with a and b, I assume it would be 36 * 6 - (5^2 + 4^2 + 3^2 +2^2 + 1^2)
this looks like something that would be in #competition-math actually
it seems like you can easily reason the same answer by constructing the points in space 
do you guys have any modules so that i can practice math specially the junior high school math im already gr.11 and im having a hard time in conic sections and linear equations, i know you guys are thinking that how did i became gr.11 well the answer is the educational system in my country sucks so i really gonna need some help i cant find any module to practice in google so thats why im asking
?
I'm not familiar with your school system, but Khan Academy is a free source to learn/review math that I like. Most of the questions are at a basic level, but they help you understand the concepts.
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How do you find the inverse of a function?
and identify the invariant point
Given an equation
To find the inverse, all you have to do is convert f(x) into y, then swap x and y. So for example, the inverse of $f(x) = \sqrt{x}$ is $x = \sqrt{y}$, or $y = x^2$
🍞 Is Toast Modern? 🍞
if you wanna find an invariant point, those are points that are just mapped to themselves, so you'd have to solve f(x)=x
Aka the intersection between the graph and y=x, right?
yeah, you can look at it that way too
Hey can you guys recommend sites I can use to study trigonometry?
Correct
No
For something to be a function, each input variable can only have one output variable max
The input '10' has two outputs, 2001 and 2003, so the table doesn't describe a function
Yes
awesome, thanks for all the help bro
ok and for this
that would be e right?
for this
is this B?
@ashen skiff if u can help :)
correct
Note that the question is asking for q(y-3), not q(x-3)
yup
thanks for all the help!
hello i was wondering if the answer to this would be arccos (-1/3)
i did the process by taking the arccos of the dot product divided by the magnitude, but just wanted to verify
something like 109 degrees apparently
yeah that's good
alright thank u!
you're welcome
This has a no removable discontinuity at x=3? Right
Because the vertical asymptote
yes
it's not just not removable, it's a discontinuity of the second kind (or so-called essential discontinuity)
This one would be continuous at x=-4 and a jump discontinuity at x=-1 too right?
A jump?
an (not always) infinite jump
a discontinuity of the second kind is the discontinuity where at least one of the one-sides limits doesn't exist
and both there don't (they are infinities, so they don't exist)
But don't they go on forever? Until x=3?
they do but AT x=3 they are just gone
Oh ok thanks
also they are not even equal, one is -infinity and another is infinity
at x=-1 a jump discontinuity, yes
and at x=-4 continuous
Oh ok cool thank you again, my teacher didn't tell me about essential discontinuity
essential discontinuity is the one that you can't do anything about, neither remove or somehow pair the parts of the functions
that's why it's called essential
Ah ok that makes sense
What went wrong here?
The exponents in your binomial theorem are off. They ought to sum to 2 in each term.
Also, you seem to be switching variables between "n" and "k" without it really being clear whether they're supposed to be the same, and you also seem to be trying to write both a summation sign and all the terms in the summation separately, which makes it hard to decipher how you thought it would work.
I'm evaluating the tan of 13pi/12 and I'm able to simplify down to "2" instead of "2-sqrt3"
I'm using the angles pi/4 in addition to 5pi/6 to represent 13pi/12
@rustic swallowruffini
9+36+(-3D)+6E+F=0
how can i find the radius with this?
i think there's something wrong with this
or nahh
im not sure
Help
@hazy hollow 2.8 radians is not 5pi/6 despite any apparent proximity
you should locate the point for 2.8 radians and give its coordinates as it appears on the graph, and rounded to 1dp
$1+1$
Karter
No silly trolling, please.
I was just testing something chill
#latex-testing, even.
King Tonberry
I was testing
Stop.
I'm new...
how do i get the model for this?
First, what is the income equal to?
Really, what is any income equal to?
so (1500-5x)?
The income is how much money they make selling cars. If they sell 200 cars at $1500, their income is going to be 300,000, right?
yes
So for a), since we're trying to find the function, we know that f(x), or the income, is equal to the number of cars being sold multiplied by the price of each car
our beginning number of cars is 200 and our beginning price is $1500
at what rate is amount of cars changing? at what rate is the price changing?
50$ for every 5 cars
right, so if the price goes up by 50, cars decrease by 5. price goes up by 250, cars decrease by 25
so for every x increase of 50, there's also an x decrease of 5 cars
so the price is going to be 1500, plus some value 50x
the car amount is going to be 200, minus some value 5x
so its (200)(1500) + 50(x-5x)?
Income = Price x Cars
The price of each car is (1500 + 50x), where x can be any value
the amount of cars is (200 - 5x), where x can be any value
so the income would be equal to (1500 + 50x) * (200 - 5x)
yup
You could pull out a 250 if you wanted to
okk tyy
that would give you -250(x^2 - 10x - 1200) which could be factored to -250(x-40)(x+30) I believe
I think they simplified the +50x and -5x to +x and -1x/10
so (1500 + x) * (200 - x/10)
why do I have to divide 4900 to 100 and 90? for e
Dividing total cost by the price of each kg will give you total kg, right? If the total cost is $1000 and the price of each is $100, you know that there were 10 items because 1000/100=10
Dividing 4900 by 100 gives you 49. That means the total weight would be 49kgs
4900/90 gives you 54.4kg, so that's another possible weight
4900/85 gives you 57.65
The problem with that though is that the price is only ever $85 when the weight is over 200kgs. 57.65 kg at $85 per kg isn't possible, so 57.65 is not a possible weight
is anyone here able to help me with a quick problem
if its factoring sure, i enjoy factoring
I figured that chain rule wouldn't be needed
if t=7, then i found that g(t) is approximately 6-7
which would leave me with f(6.5) or so
then i took the derivative of that 😅
we aren't given exact values so I can't plug in anything
Looks like you have fairly accurate graphs to me
Also definitely do not make the mistake of assuming that the derivative of f(g(t)) is the derivative of what g(t) is like you did, you'll get it wrong.
That's because the derivative of f(g(x)) is f'(g(x)) * g'(x) and that g'(x) is important
i forgot. when the degree of the numerator is larger than the degree in the denominator, what do we get? (vertical and horizontal asymptotes)
it's more obvious on fullscreen, g(7) is definitely not an easy number to see
it's just slightly less than 6.5
Yeah, I just approximated it to be 6.5
here are some cool precalc notes i took
Nice handwriting, do you practice?
yoo I wish I was that neat >w<
yes
thank you 💚
np
An explanation of an overlooked method for solving quadratics, and an argument for reshaping how we think of and teach mathematics from a high school math teacher.
Foundational Videos Link: (Coming Later!)
Contents
00:00 - Introduction
00:35 - Foundation Pre-Check
01:06 - Cancelling
02:20 - Factoring
04:36 - Foundation Check
05:28 - The New St...
at least some of you will find this helpful, thank me later
Hello, can someone please check the validity of this proof I wrote please? I'm pretty sure it's fine but a second opinion never hurts
please ping 🙂
If it's homework and you don't have any particular points in the proof you have doubts about, why not let your teacher/grader do the checking? They get paid for it; we don't -- and it's tedious and boring work.
It's not homework, it's self study
I'm in britsh HS and each time I ask my teachers about any proof based things they just say they can't help me
You don't have to check it if you don't want to tropo, no one is forcing you, just if anyone would like to be a helping hand I would appreciate that - especially given I Don't have anyone to check my understanding against irl
can anyone explain what is happening here and why (dont mind the phone brands)
were trying to find the radius with point (3,2) and (2,1)
also dont mind the subconscious thing
lol
Do you trace or just write?
i don't trace
hmm cool, good stuff
Anyone know of the best online courses for precalculus that do a good job at making the curriculum make sense? Everyone in my class just failed the last test, so I need to figure it out somewhere else
Looking at this reminds me of how much easier life used to be 💀
What lol
Calc 1 and 2 are way harder than what pre calc guves
ahh yeah i bet
I honestly don’t remember anything from pre calculus because of how much reg calculus is drained into my head
hey im reviewing my study guide for the test tomorrow and don’t understand this concept
i dont understanding how the -x^4+12x^3+3x^2 was gotten
could i just add the exponent and call it a day?
They multiplied the divisor by x^2 to get a leading term of x^4 that would cancel out
se
How can you tell if it’s defined or not
I already did the other parts I’m just confused on the first part
if the denominator is 0 then it is undefined
NotMyself
So x =3
yes
I’m trying to tutor someone pre calc but I don’t remember this
oh
I don’t remember translations with asymptotes lol
Is there any reason for me to learn "complete the square" or can i just always use the quadratic formula?
it's useful for converting stuff to different forms
helps with graphing, identifying vertex, max and mins
and later on very useful when working with circles,eclipses,conics
and the idea behind it is also quite handy for some questions involving algebraic trickery
note that there should be a distinction between completing the square itself, and solving a quadratic equation using completing the square
i.e for
x^2 +2x = 8
x^2 + 2x + 1 = 8 + 1
(x+1)^2 = 9
CTS only refers to the part up to here
definitely shouldnt skip
alright, thanks, i appreciate it
it's also a good exercise to derive the quadratic formula using completing the square if you haven't already done so
Is there a good video(s) that explain all this in good detail?
I cannot rn
it only works if the discriminant above or equal to 0
its another method to use if quadratic formula fails
qf doesn't fail
it works if discrim<0, u just get complex sols
o'
I had a odd question, would anyone know any “assignments” or practice problems for pre calculus that also have a solution sheet that is based around space? Like I would like to practice more of my pre calculus but I thought it would be funner to do if it was based in physics or space
are there any free websites that have precalculus lectures and practice problems?
Khan Academy
tan(k) = sin(k)/cos(k)
factor sin(x) and now it's an easy equation
should be (x+pi) everywhere though
then also make sure none of the roots turns cosine into 0, if so exclude them
you can factor out sin(x+pi) at the very start
which makes the work considerably less tedious
Good idea. Though, Transparent Elemental, what do you mean by "should be (x+pi) everywhere"?
All of the terms with pi were cancelled because of their relation to sines with the input of pi
that's only true for tangent here, sin(x+pi) in general isn't equal to sin(x)
The graph of sinx isn't identical but the solutions are
The right side of the double angle equation for sin is equal to 0 because it's multiplied by zero (sin of pi)
In the top image it should be -2sinx though
Sorry for the trouble, I just want to understand all aspects of the problem
Can i get help with this, i genuinely attempted it and i don't understand how i'm getting it wrong
So, what about between 0 and 1 in the domain...
yep
no, there's one more
which depends on what a is equal to, whether it's greater than 1 or less than 1
oh sorry, I thought it was checked for some reason
so it should be unchecked
so you're good
Had me confused there for a moment lol
Yessir, we're up
How would you find the reference number for t=5pi?
I'm not sure what the "width" of the bridge refers to...
Considering the height however, a classical parabola is closest to the x-axis at x=0
If we shift the graph down (-27), the deviation from the x-axis is greatest at x=0
If "h"= height, that would mean (based on the graph of the equation) that the bridge is tallest as x approaches -infinity and +infinity
This however doesn't make sense so I would assume they are talking about the point of maximum deviation (negative) from the x axis which is -27
The reference angle (from the unit circle) is the angle between the terminal side of the angle and the closest x axis
how is this wrong
yeah the question
is phrased horribly
i thought the same tgunf
It's semiannual right?
beo
bro*
use I=PRT/100
use that fromula
for*
I am IGCSE O level Student
yes
What do u mean??
add me so we can discuss this in dms
ok
What have you tried?
@mild swan can you answer this
i think it is inequality
is easy
“Is easy”
Grammar isn’t, it seems
maybe
Hi, what's the fastest method to find the determinant, the inversion , the rank and the singular of a 3x3 matrix matrix?
how do i solve this?
if there's 8 children, the probability of having either a boy and a girl is 50 percent, What's the probability having 6 girls and 2 boys?
Can anyone help to answer this question pls
f being its own inverse means f(f(x)) = x for all x
and with that Ill be able to find the value of K?
i dont understand this
(a) I do not understand what "f is its own inverse" means.
(b) I do not understand what "f(f(x)) = x for all x" means.
(c) Both statements in (a) and (b) are beyond my understanding.
(d) I understand both statements in (a) and (b), but not why they mean the same thing.
which of these best describes your confusion?
thank you for not answering my question
d
who pinged me here
right ok so
you understand that when we say two functions are inverses, we mean that their composition is the identity function, yes?
yes
right
and you understand that when we say a function f is its own inverse, we mean that the composition of f with f is the identity function, yes?
yess slr
when the function has f(x)
you talk like a survey
how else am i going to discern where exactly the help-seeker is confused if not by giving them a list of options to look through
im just saying
my most unforgiving mistake 😫
isnt this the u v v' v' thing
like u just flip the sign of the imaginary number
i honestly forgot lmfao
You mean "complex conjugate"?
one think we do know: Shinkansen is absolutely DOMINATING these imaginary division problems
why is sum of odd powers factorable but not sum of even powers
Uh, what?
A polynomial that has only odd powers will always be divisible by x (just by virtue of having no constant term), is that what you're talking about?
my guess was gonna be that they mean you can factor x+y out x^n+y^n when n is odd
Oh, that sounds more likely.
Pretty much lmao
yes this
I suppose if that's the question, then one explanation is when you look at x^n-y^n=(x-y)(x^{n-1}+...+y^{n-1}) and replace y with -y, it only changes to x^n+y^n when n is odd, otherwise it squares the -1 away and stays as x^n-y^n
+.....+ +........+ +......+
x^5 x^4a x^3a^2 x^2a^3 xa^4 a^5
-.......- -........-
Each of the +.....+ or -......- stands for a monomial times x+a possibly times -1.
Becasue positives and negatives alternate, all of the middle terms cancel each other out, so there's just x^5+a^5 left at the end.
But we need the last link to be a +......+, otherwise we would end with x^n-a^n instead.
Another explanation is that x^n+c^n (c nonzero) has a real root (x = -c) exactly when n is odd (and hence we can use factor theorem)
If I learn everything from this YouTube Playlist, will I pretty much be set up for Calculus?
Knowing math isn't the same thing as being able to do it..
Well yeah, I wouldn't just watch the whole playlist with the intention of not being able to apply the information, I'm just saying if I do properly learn everything in that playlist and am able to apply that info properly, would that suffice me of all of the pre requisites I need before taking calc 1
I'd say you don't have to know equations/stuff in polar... well, you'd better do, but it's rather complementary in a way
Im not sure if im in the right channel, but is there a simple way to solve that kind of summation ?
i mean j instead of i
split up the summation and solve indiv parts
^^
take the sum $\frac{x^{k+1}-1}{x-1}=\sum_{j=0}^k x^k$, take the derivative of both sides, multiply by $x$, then plug in $x=2^{-1}$.
Merosity
just realized this is precalculus channel whoops
how do I find all solutions and the fourth roots of -81i
when 0-81i tan = -81/0 is undefined?
What do you do when you have no angle?
wait i think i got it
if it appears on the axis we just pick the angle for which axis it lands
Do someone know how to find area of this one?
does anyone understand proving trigonometric identities?
WHAT IS A NATURAL LOG I DON'T UNDERSTAND
do you know what ln(x) is?
Nah, also sorry for posting in all caps, that came off too strong
But yeah I just don't understand, I think its a log with a 10 base always
nah dw about it
oh no
its not that
do you know what the e in that picture is supposed to mean?
i think its supposed to be an a, it was in all the other problems but suddenly they changed it
uhh
i believe that's euler's number
it is a constant, like that of pi
How will that work
can i get help with this
you've entered a constant funtion
starting with f(x) = a^x
plug in the given point to determine the value of a
and you'd enter
(whatever you got for the value of a)^x
so plug in 1/3 into f(x)
plug in the whole point into your equation
and/or sub x=-1 into the equation, the point tells you f(-1) = 1/3
multiplicative inverse yes
so then the answer would be 3
The “reciprocal”, to be precise
oh, alright
well your value of a will be 3
and you'd enter
whatever you got for the value of a^x
yes
Can someone help me with this 😭😭
I get m=4 and k=1
which is incorrect
could someone help me understand where im going wrong
- why are you asking in here
- why did you ping me in particular
- ok
but I know you were specifically told to DM mod mail 
can anyone help with physics queestion?
Also see #old-network to find the dedicated physics server.
can anyone give me tips on getting started learning pre calculus
Khan Academy and Youtube
organic chemistry tutor
khan academy explains it better
how quickly do mods see it if u dm modmail 
how do i evaluate the limit of this expression as x approaches 1
(not allowed to use l'hopitals rule 🥲 )
Ok so first, what is the l'hopitals rule
Cus like, personally I would just multiply by the conjugate
That might be a good start, but will still leave you with a denominator that approaches 0.
doing some stuff with conjugates should work
split it $\sqrt{x^2-1}/\sqrt{x-1}+(\sqrt{x}-1)/\sqrt{x-1}$ and the other part
Amer
The first just factor top and cancel
for the second conjugate the top it is double the denominator so it is zero
the limit should appraoch from the right of 1 if not you will be out of the domain
So, do you know what happens when you change x^2 to 2x^2?
Or when you change x^2 to x^2-1?
Basalt
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
does anyone have any idea how to solve this?
@tall sequoia Question . Im trying to convert -225 into radians. I got -5pi/4 . I know that its going to be -225 * pi/180. I broke down 225(455) and 180 (454), after canceling everything I ended up with -5pi/4. I looked up the answer and its -37/30......where did I go wrong?
(Pinging modmail does nothing, by the way -- but that's just as well because math help is not a moderator matter).
Who says the answer would be -37/30, or for that matter -37pi/30? Don't trust them.
can anyone help me get better at pre cal 12 i have been studying 4 hours a day everyday and i still dont get it i think i have a problem in my fundimentals that need to be pointed out. can anyone help?
You can try talking about the problems you have here -- but you'll need to bring up the specific things that confuse you; there's not much one can do if you just expect people to take the initiative from scratch.
Its pretty hard to give an exact problem because on matter how much i study i keep making mistakes and im hoping somone would be willing to do some questions together and seeing why i am struggling so much
If you're not willing to say anything more specific than "I keep making mistakes", nobody will be able to help you. Sorry.
What’s the formula for the last one
<@&286206848099549185> pls
I don’t understand what h and k are
Nvm lol
A person has 2 parents. 4 grandparents, 8 great-grandparents, and so on. Find the number of his anscestors during the ten generations preceding his own.
Isn't the above question wrong as there might be someone who had kids with 2 people and then predecessors of those kids married and stuff like that
You're correct, but I don't think you need to think about that in order to solve the problem.
will ig but they should have mentioned
Well do you need help with the problem itself?
no thnx
Alright
Pictures will do
How about a rice hat? Not just conic sections, but an actual cone!
@hollow scaffold don't ping everyone.
Ok
NotMyself
NotMyself
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
Is this proof right?
<@&286206848099549185>
ill check it out later
arithmetic progression
i should go back and restudy pre calc
ohk
$S_n = \frac{n}{2}(2 t_1 + (p-1)d)$ I would use another variable for the first term i used $t_1$ instead of $a_1$ because they used $a$ to denote the sum of the first $p$ terms becareful do not sub a in the sum of the first p terms!!
Amer
so your proof is not correct you assumed first term is equal to the sum of the first p terms
for both questions, try to factorize the denominator and divide the factors from the numerator
Ty
do u guys think it is necessary to memorize the entire unit circle
depends, once you know 30 and 45 degrees the rest all come from that by symmetry
Necessary? I don't know.. Worthwhile, yes
\text{ For two complex numbers, $z_{1}$ and $z_{2}$, where; } \\
$z_{1} = a_{1} + b_{1}i \\ z_{2} = a_{2} + b_{2} i$ \\
\text{If $a_{1} = a_{2} = 0$ then can we say that $z_{1} \cdot z_{2} \in \mathbf{R}$ ?
}
∫Inheritanc-e ♦
yes.
thnx
yes as i^2 = -1
The entire unit circle is far too much. Textbooks usually list coordinates for points with angles that are multiples of 30° and 45°; as Merosity says these can all be derived by symmetry if you just remember those two base values.
There are other exact facts that could be remembered, such as cos(36°) = (1+sqrt(5))/4 -- but nobody goes around actually memorizing those.
all you need to know is 45 degree triangle and 30-60 triangle, can derive basic stuff from that. for tips you can look up youtube videos, how to memorise it.
I wouldn't dedicate too much time to memorizing those results. Just remember that there are nice values for 45-45-90 and 30-60-90 triangles and derive the actual values using the pythagorean theorem when you need them, until you've done that often enough that you just remember them anyway.
Can anyone explain the property log base a^b of x is equal to reciprocal of b times log base a of x
$\log_{a^b} (x) = \frac{1}{b} \log_a(x)$
Ann
this?
Yes
applying the change of base law
$$=\frac{\log_a(x)}{\log_a(a^b)}$$
ℝamonov
the denominator will be b
Oh I got it thanks
do u know how when dividing a polynomial; if a term is not there, you have to hold it with a 0?
does that only work with synthetic division or does it also work with long division
,tex \polysyntheticdiv{15x^4+10x^3-6x^2+14}{x+2/3}
babytronfan221
\polysyntheticdiv{15x^4+10x^3-6x^2+14}{x+2/3}
```Compilation error:```! Undefined control sequence.
l.57 \polysyntheticdiv
{15x^4+10x^3-6x^2+14}{x+2/3}
The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.```
in polynomial long division you'd write 0x^(the missing power) or leave an appropriate gap to keep stuff aligned properly
heres some cool precalc notes i took #2
I need help with these
I already have #6 down
I dont want answers please
i just like to understand what I should do to go about solving these
How would the black function looked algebraicly?
What would be the transformation from the black to red?
god damn i wish i had notes like that
Down five, right three
wouldnt it be down 5
What would the original function look like? The black one
the function might be a piece-wise function, like it's split into 2 equations.
maybe something like this
yeah
wtf is sin of -90,
-1
thats what i got and someone told me it was wrong
i guess dont listen to them idk lol
-0.8939966636
ive been sitting here for 2 hours just dumbfounded, i thought i was the idiot
did the put it into the calculator?
Or -1
its -1 on the unit circle
idk, i just remember the unit circle, but they made me second guess myself
they prob had their calculator in radian mode and put -90 in
@proven spear it should be -1 or -0.8939966636
so it thinks its -90 rad
they wasted so much of my time
Yeah it happens
you have your calculator in rad mode so it thinks the -90 is -90 rad
thats where you are getting the -0.983
sin(-90degress) is -1
Yeah lol it's -1, my calculator makes it confusing between rad and deg
its all good
how do u evaluate tan from unit circles?
give an example and i will try to help
tan(theta) = y/x
ill give example
yes
kk ty
isnt it the same as a regular graph?
wdym
like the signs for each quadrant
like quadrant one is all positives, quadrant 2 is x negative y positive and so on?
yes
like the special angles?
yes
practice
45degree angles are the same
like with sin and cos
sqrt2/2
30 and 60 are harder to remember
hm
right
just alternate them for 30 degrees
kk ty!
try to remember which is 1/2
what are coterminal angles?
and build of that
kk
its angles that are 360 degrees apart
so you take the original angle and add 360 degrees to it
or subtract it
you go counterclockwise 360 degrees
if you add 360
or you go clockwise 360 degrees
if you subtract them
like this
OH okay
could you like give an example?
what would be the coternminal angle for 500 degrees
i'm sorry i keep asking questions
its ok
im free rn
so
if you are looking for coterminal angles
you add 360 degrees to the angle
so like it would be 860 degrees?
I don't want to interrupt yall but can you help me after please
and you subtract 360 degrees
to find counterclockwise?
whats up
do you know anything about the functions of sins and cos? like moving and shifting.
I just learned about coterminals as well but different
f(x)= cos(4x)
I know its moving 4 times as fast as cos (x), just don't know how to find the measure points
oh no we arent there yet
oh haha, its okay
when you add 360 you are going counterclockwise
if you have a negative angle you would move clockwise
add 360 = counter, subtract 360 = clockwise
yes
that explains a lot tysm!
np
the 4 basically makes the wave tighter if that makes any sense
like if you were to graph it
yeah, so y stays the same, but x is 4 times shorter?
Can anyone help with synthetic division when the divisor is prime numbers
yes
wdym
ya thats what I wrote but I dont think thats it
like your talking about when I do the synthetic?
okok yk how I would write it out after synthetic division finding the remainder and quotient
and division statement ?
what is left over (the remainder) over the quotient
i think
like [remainder]/3x+2
can you help @viscid thistle
pls
wait wym
i deadass might die
honestly i don't remember a thing from geometry, did that course over pandemic
i'm sorry i wish i could help!
Anyone know the end behaviour, turning points and global max/min of a function with a degree of 59 and negative leading coefficent
what pen and whats its longevity
it's a pilot precise V5 extra fine pen
my absolute favorite pens
nice note you got there
Can someone explain the difference between closed and open circles? Like if the question is:
lim f(x)
x->-3 from the left, is that 2 or -2? Same for the right
the very definition of a limit doesn't care about a circle
the circle represents whether the function is defined at that point or not
if you take any sequence of inputs that converges to -3 then function value would converge (if the function is continuous) to values that should be near that point
so it's 2
Demos doesn't let me graph like that for some reason
@feral lake do you know what the original function is?
@feral lake oh ok cool thank you
The brackets are for the interval
Ah ok thanks
What do you mean?
For example, the original black function is f(x), how would I graph the red function?
@viscid thistle when I try I'm doing something wrong
Looks like a scaled version of the black function.
Anyways.
Just calculate the slope of the red line for 0<x<2, so you can write the line for that interval.
And when 2<=x<=5 it'll just be y = 1.
Or do you mean how to graph it on Desmos?
The way the other guy did?
@viscid thistle oh wait I got it thank you anyways
Hello^^ im so sorry ;-; but can someone help me factor this one out im begging
im trying to get the zeroes by using synthetic division and so far i cant get any correct ones from it ;-;
then do i resort to factoring if theres none?
you can't factor this most likely
oh no 😭 how will i graph this then?
I guess there's always a quartic roots formula, but you don't want to ever use it
you can use certain methods to approximate roots
you can use derivatives to identify locations of stationary points
take the derivative, find local minima, analyze how the derivative behaves i. e. where the function is increasing or decreasing
that should be enough for proper graph
and pug in as many other values of x as you want to get enough points to make your graph look decent
I actually got one location from it and its -8 but so far for the others i cant-
im sorry to say this but i dont think i can use that-
then you can't do anything about it, besides very long and boring plugging x's in the function and marking the result
actually theres choices and i know which ones the answer the problem is the problem our wack teacher gave us isnt factorable at all
is this one at least factorable though?
I guess not
god i hope whoever made our worksheets 💀
ig ill just identify it based on the end behaviors
TYSMM THO^^ @summer ruin @uncut mulch

hello, if you had a function f(x), where x is the variable, and f(x) is the function, what does f represent?
is it just a placeholder?
I have questions that are like this
find the domain of $$f \circ g$$
smoobles
well actually f is the function
"f(x)" could used when describing what the function f maps each x to, or it might be used to represent the value that f maps a particular value x to
depending on the context
ah I see
doesn't it get confusing when you have functions and variables in the same field?
like I know f can be either (f)unction or (f)requency in physics
it could but I think people are usually good about that when writing things
actually I take that back
it's pretty confusing for people in differential equations
I hope no one in physics names a function f when they are already using f for frequency
normally nu is used for frequency tho
parallel to the line 4x-2y=8 and has the same y-intercept as the line 5x+3y =-15, can someone tell me the point slope form of this?
Of course it is
Use the factor therom
Are the increasing intervals (-infinity, -1)u(-1,1)?
having some problem factoring this expression (x^2+x+6)
It’s one of my roots for linear factorization but I can’t get it as two binomials
I don't think that's factorable
Yeah I know but I need it as a complex root
You can factor it using the quadratic equation
If it is a polynomial with a degree of 2, then you can always rely on the quadratic formula
Wait just remember to use the opposite sign
Yep
I have a question if someone can answer pls
For Remainder Theorem…
Am I supposed to plug in the c value to the x??
Someone explain 4 to me pls :))
I'm confused
How do differentiate a infinite discontinuity from just a continuous function?
what is an infinite discontinuity?
Theres a infinity at a positive and negative asymptote?@wise rover
I'm not sure 100%
Read your notes
Thats collatz conjecture and its still unproven
tho it has been verified for around 2^60 numbers
translate cuz i speak spanish and idk how explain this in english: mira, la discontinuidad de los lomites es algo muy simple, sucede cuando sus evaluaciones laterales del limite, (derecha e izquierda), son diferentes, pues por ejemplo, una función de raíz cuadratica de x, donde x tiende a 0, cuando tiende por la izquierda se forma una raiz cuadrada negativa, lo cual indica numeros imaginarios, por lo cual no se puede representar de forma gráfica, PERO, evaluandolo por la derecha si se puede pues son raices positivas, entonces su limite no existe. También es fácil de ver cuando tienes una función definida o también llamada función a “trozos”, que cuando hay un valor en un intervalo se define valor de la función diferente al del otro intervalo
Hey everyone, we've recently started learning about limits, but im noticing that no one really understands what a limit is.
I asked my teacher and he didn't give me a definite/clear answer of "What is a limit", i checked on youtube and didn't find many resources.
I first thought it might be the "limit" where we go up the y axis and stop at a certain point (which for me explained why f(x)=x/0 has no limit, because we will go up the y axis and never stop. I'm not sure though.
Where can i find the exact definition of what a limit is?
hello, i am starting to learn differentiation (on my own), does anyone have a source where i can get questions from
where i can use things like the chain rule, product rule, quotient rule, etc
Yea im trying to find questions as well
the limit is formally defined as https://en.wikipedia.org/wiki/Limit_of_a_function#(ε,_δ)-definition_of_limit
In mathematics, the limit of a function is a fundamental concept in calculus and analysis concerning the behavior of that function near a particular input.
Formal definitions, first devised in the early 19th century, are given below. Informally, a function f assigns an output f(x) to every input x. We say that the function has a limit L at an in...
(for your purposes)
My teacher told me a limit is the study of a function at a certain point, simple and clear lol
And x/0 is non defined because the denominator is 0, so there is no correspondent on the y axis
It's like bargaining at a store, you keep going up and the retailer keeps going down till you both meet at a point
if you dont meet there is no limit
:)
how do you find the angle measurement between 0 and 360 with 9cos+7=0
But im trying to understand the calculation so the furthest I get is cos=-9/7
What’s where the mistake is
You need to be careful when moving the numbers around
Wouldn’t it be -7/9?
Ah yes thats what I meant, apologies. My meaning still stands that I do not know how to find the the angle measurement with this information
You need a calculator
Need to understand how to do this, as well as many other similar topics before the end of next week.. aha
do u know abt the power laws? theyre pretty similar
smoobles
why does it give me $-\sqrt{2}$ on the table
smoobles
I don't think there should be real points in the graph for rational x values
cause the graph is the negative of the exponential function {let say f(X)} and the domain of an exponential function is - (R) and its range is R+ (0,infinty) and you are operating the negative function on f(x) so it would only give you -f(x).
not f(-x)
You typed in -2^x, which is interpreted as -(2^x); instead try typing in (-2)^x.
ah I see thanks
mhm I got that now
yeah unit test
An asymptote
how do i convert 25 into a log with base e??
ig this is how u do it
NotMyself
NotMyself
how to solve this?
i added 20 and divided inequality by 25
But idk what to do after this?
NotMyself
15 year olds here know trig better than I know the alphabet 😵💫
You're an inspiration
btw i wrote [0,pi] 2 times by mistake
nvm got it solved
Hah u must be in 8th grade
i do math 55
lie alg
the statement of the remainder theorem is that (x-b) divides p(x) if and only if p(b) = 0
So if we let a = -b we can equivalently say that (x+a) divides p(x) if and only if p(-a)=0
so u cant answer my question?
Can anyone explain how to convert a trigonomic function fraction like sin root3/2 to a pi value? I don't understand how the pi values are found
trigonomic function fraction?
Are you familiar with the unit circle?
I think you're asking about basic inverse trig functions?
are you sure you want to calculate sin(sqrt(3)/2)? and what's a "pi value"?
i think he meant sin(x) = sqrt(3)/2
you've got unlimited possibilities for x
but we can generalize them into two solutions with an integer parameter
in this case x = pi/3 + 2kpi or x = pi - pi/3 + 2kpi
it's always like this with sine functions
how to find reference angle with cosx=-7/9
the last one is a function
it's called a constant function
polynomial of degree 0
y is not defined, so it isn't even in a set (for the last one)
x € R is correct
so it would be ∅
for constant function x=4 the range is a set that consists of a single number {4}
and if the function is called x you better not be using x to mean values in the domain
so what values would i use
? wym
this doesn't make much sense if you think about it
that wouldn't even be mathematically correct
because the range of constant function is not the entire real line
true
You can compute directly what k must be in order to get f(f(k))=2 to be true.
Just expand f(f(k)) using the definition of f, simplify, and then solve for k.
can someone check if this is right
seems correct, but does your teacher expect you to write single points as [a,a]? it's a little silly.
seems okay, for a you shouldn't write equations as intervals, only points.
Im sorry but ive been trying to check my answer all night for this but no one is responding
heres some cool precalc notes i took #3 (finally on logs!!)
@sterile turret do you still need help w/ this
how do i find the domain and range of the square root of a quadratic equation ping me if u know
yes
okay
do you understand that, from what is written, you can directly get the equation of the slant asymptote as y = ax+b?
and that the x coordinates of the intersection points of the graph w/ its own asymptote, if any, are given by the equation ax + b + (cx+d)/(ex^2 + fx + g) = ax + b
@sterile turret
oh god... I accidentally thought that you have a comma after the asymptote and the problem turned into a much harder one
(I thought that the asymptote itself has the form ax + b + (cx + d)/(ex² + fx + g) and N(x) and D(x) are arbitrary polynomials)
i know that one of the zeros is 4+i but what is the 5th? and how do i find it
as stated you cannot even say that 4+i is a zero lol
really?
well who said the polynomial had to have real coefficients?
kunny
depends on your interpretation of the right hand side
well you didn't specify what is x and what is y
or which set they come from
right hand side can be interpreted as a constant function
it takes x, doesn't do anything with it and outputs a single number y
while the set notation doesn't even specify what you would do with each input, it just says you take something in X and transform it into an element of set Y
whats the law of sines AAS and ASA about
can anybody help me solve this
the answer key says between 2020-2021 but i just can’t seem to get that answer
its an issue with your usage of the rate i believe
convert 1.49% to decimals first
so div by 100
which is 0.0149
and since it said it is increase by that rate
you add 1 to it
otherwise it would be decreasing if you leave it as 0.0149
does that help?
wait
is this differential equation?
is this a function
yes
in a function every value of x corresponds to only 1 y value so yes
but doesn't it have a single x value for multiple y values at -2 and 2
or is the difference so small in the graph it looks like a straight line
yes it is a function
and that looks like a line
that is allowed
hey
well you clearly did it wrong then
division
that would imply the theorem is incorrect, which we know that it's true
idk what that synthetic division method is so I can't check if it's valid or not
Bruh
@summer ruin the theorem is true, I got 0, but when f(2) I don't get zero
When I did it synthetic division I got 0, but when I did the remainder Theorem I didn't get 0
you would get zero if (x-2) was one of the roots of the polynomial
clearly you have a contradiction
If f(2) you would get -2
well what's the question you're trying to ask then?
So it's not a root?
you think your result is correct yet it violates the theorem, there's really not much to suggest besides looking for a mistake in your work
If (x-2) is a root of the polynomial
clearly x=2 is not a root as f(2) != 0
but you somehow got 0 out of division
which isn't possible
therefore you made a mistake somewhere
I used synthetic division correctly, but it doesn't work considering f(2)
Which again makes no sense
,w synthetic division (3x^5-7x^3-11x^2+2)/(x-2)
somehow the remainder happens to be -2
I know
then it all makes sense now, the remainder is not zero
If it is illegal to “cancel” out trig functions in equations, for ex: tanxsecx = -3tanx -> secx=-3 by diving both sides by tan gets rid of a solution. Then why are we allowed to multiply by sinx/sinx? Wouldn’t that also cause domain changes?