#precalculus
1 messages Β· Page 59 of 1
desmos doesn't explicitly tell you about open holes
if you hover over tan(x) cos(x) it doesn't do that
weird
i guess it doesn't recognize there are open holes there π
it depends a lot
i know desmos is wacky about open holes but i guess i dont know exactly what it trips up about π
cos(pi/2) = 0
tan(pi/2) = undefined
yup
why multiplying it equates to 1
it doesn't, but if you take the limit approaching pi/2 it does
basically, it approaches 1 but doesn't equal 1
tan x = opp/adj
cos x = adj/hyp
(opp/adj)(adj/hyp)
opp/hyp
sin x
what happens if adj = 0?
tried a bit of algebraic manipulation
undefined at that value
exactly
well, idk
maybe
you can't work with tan(pi/2) then
but you can take the limit as Vicious Viper said
in the context of just straight up functions, 0/0 is undefined
as in $\lim_{x \to \pi/2} \cos(x) \tan(x) = \lim_{x \to \pi/2} \sin(x) = \sin(\pi/2) = 1$
these are all indeterminate forms
southlander!
use of manipulation
outside of limit context, 0^0 i think is defined to be 1 π
i understand now
idk
if 0^0 is 1 or undefined
the concept is
actually nvm wiki says it depends on context
you should:
- take the limit
- simplify the expression inside the limit
- now you should be able to sub in an x-value directly, if you did the right thing for 2)
yeah
to find the limiting value of something that is undefined
try limit of x^x as x approaches 0
because desmos recognizes 0^0 as 1
you could also try 0^x as x approaches 0
but yeah
there's a very good reason why a lot of mathematicians define 0^0 = 1
binomial theorem for instance
and stuff to do with empty products
everything outside of calculus says its 1 lol
interesting
does limit of x^x as x approaches 0 exist?
i dont understand anything
like x/x = x^0, why x/x is undefined and x^0 is 1
x^0 is more of a convention thing
x/x = x^0 for x β 0
0/0=1 0^0=1
division property and exponent property i dont understand the problem
0/0 = 1??
a/a=1
......
0=a
that's a rule which holds for a β 0
therefore 0/0=1
dividing 0 elements into 0 sets means there is 1 element in each set
well actually there could be 0 as well
because 0 times 0 is also 0
or 5
because 0 times 5 is also 0
maybe 0/0 should be considered undefined or indeterminate because any number satisfies 0/0=x because 0/0 (0)=x (0) 0=0x 0=0
yeah this is the reason why
like dividing an empty set is by definition undefined
there's just nothing to divide
as you probably know 0 is not the same thing as the empty set
so 0/1=x
0=1x
0=x
i divided nothing and got nothing
you didn't divide by 0 tho
but i got nothing not everythnig
also I'm talking about partitions of an empty set
that's not the same as dividing 0 by something
ahh
I think it does
It's like one
(It's one)
limits are #calculus , and the limit is 1.
we were the ones who brought up the limit stuff 
also they sometimes introduce limits in precalc
any specific one
trig is screwing me
got my unit exam tmrw, i got a good understanding of the graphing aspect (70-80% ish) but i got a 40% on my unit circle quiz
I got like 90 min to study, what would u recommend i study?
the unit circle cause it's super important
if you're not confident with the unit circle I'm pretty sure you're not confident with solving trig equations
namely, that if sin(x) = k, then sin(pi - x) = k also, or that pi - x is the 2nd solution in a period
similarly, cos(x) = k implies cos(2pi - x) = k, so 2pi - x is the 2nd solution
tan(x) = k is the easy one as there's only one solution per period
In this video I go over an overtly detailed analysis of the trig identity sin(Ο-x) = sin(x). I go over the simple proof of it but then illustrate how the graph of sin(x) gets shifted to the left by Ο and then flipped vertically and ending up coinciding with sin(x). This is an interesting trig identity because it's unlike the usual trig identitie...
this might be useful
if you understand the unit circle, the sin reflection identity is across the y-axis
sin theta = y = height remains unchanged
the cos reflection identity is across the x-axis
cos theta = x = width remains unchanged
so don't memorise all these identities
understand them by thinking about x and y on the unit circle, where things are the same
My precalc teacher taught it like first week
I'm cooked
hello can someone help with complex analysis
I need to calculate this by hand using residue theorem
Probably go to #real-complex-analysis
ok thank you
hey sorry guys, I cant get an answer in math-help, so posting here. Are the maximal elements {3,5} and the upper bounds as well? I dont really get it :/
Did we divide the 6 by three?
seems like you just did 4-6?
That isnβt me btw itβs from a video of someone teaching functions
I assume the 4βs went bc of compensation but idk if it makes sense here
Wait correct me if Iβm wrong
But the 4 went with the 6, then he substracted the 4 with the 3= 1
Whats up sd director
Hey
How do i identify a graph that varied from sine or cosine
Idk if this is sine or cosine
Yeah, i wanna know how to identify
Cosine starts at the peak of the wave while sine starts at zero. You can recreate that graph as either sine or cosine if you wanted to
Just by shifting it horizontally
Oh ok thanks
I have a question. Can I manipulate both sides of an equation to prove a trig identity? Or would I have to make the more complicated side look like the less complicated side without changing the less complicated side?
most teachers frown on mixing sides
you could get around that by doing stuff like
given the goal is prove
a/b = c/d
starting with the left,
a/b =a/b * d/c * c/d
and simplify the bolded part to 1
= rhs
Ah, I see. Thank you so much!
Hi,
Im a high school student. Our school is conducting a maths club in which everyone has to submit a working model (it can be related to any topic in maths) so im a little confused about the working model so can anyone give me some suggestions for my project that would be really helpful i want to present my best at my max potential for this project.
Thanks
β« (cosh^3(x) * sinh^2(x)) dx
,w integrate cosh^3 (x) * sinh^2 (x)
https://ibmathsresources.com/maths-ia-maths-exploration-topics/
here are some topic ideas
he asked it in a helpchannel
yeah it's by parts knew it
Thankyou π€
no worries!
Can someone explain how the domain went past -2?
It dosen't
I think the domain is the red line which goes from -2 to +infinity with a discontinuity at 3.
Iβd like to receive support for this question
for any function, the inverse function is just going to be a reflection of f(x) across the line y = x
also you can Google what the equation will be
"inverse of exponential function"
so like maybe it would be worth plotting individual points on y = 3^x
then reflecting them and joining the dots
rather than trying to calculate log3 (x) for a bunch of different x values
just saying
no worries, happy to help
Tysm
Ah you don't have the graph of 3^x ooops
Anyways if you have it
Os this actually a precslculus question
It's D
What is this abomination
A super roided up one
completely random conclusion unrelated to anything else presented
Not how complex log works on complex but ok. Its completely wrong anyway
you cant have this
Kid named complex logarithm:
You can have it if you're brave enough
But there are multiple possible values of it
Because of periodicity with e^{ix}
,, \ln z = \ln(r e^{i\theta}) = \ln r + i\theta
cloud
i forgot we were in the complex plane π
Makes sense on complex but its a whole set and not a single value
Sub in the values from the table
also why did you delete the image
I was going to say that the amplitude = (max - min)/2
one of the variables gives you the amplitude directly
yeah
Yea it can be calculated through $\int^2_0 x^2 dx$
Luh Roub
so it calculates the orange part
This is a fun equation because it looks stupidly complex but all it is is algebra used in pre calc
fun problem
can i solve it for you guys orrr
do i wait
Here's one: e^5 = sqrt 2x
Would i just solve for e^5, then square them to get rid of the sqrt on 2x, then divide by 2?
making sure my math is mathing
idk what u mean by "solve for e^5" but yes
Goes in the same realm as logarithms and such
I don't really know what it means but anything that is e with an exponent is solvable basically
i think you're thinking of if there is a variable in the exponent
(e^5)^2 = e^10
Well, i know you can do stuff like this
I figured solve for e^5 which is a definite number, then i should be able to give both sides an exponent of 2 to get rid of the sqrt on the right side
ln sqrt 2x = 5 is the original equation, sorry
yes. your goal is to solve for x, not to solve for 5 tho 
Which i should be able to do by writing in expoential form?
yup, just putting it into a calculator will give you a few digits of the irrational form rather than the closed form
yeah
What is e^number used for in the world, anyhow? I don't even know what it is other than the. . . inverse of a natural logarithm, which is the . . . inverse of an exponential function?
I think i have that right
you know what pi is right?
roughly equivalent to 3.14, and is used in cirlces to determine area and diameter?
That Pi?
what was the eponential parent function again?
you mean e^x?
I remember something about all expoentials sharing a coordinate
huh?
lemme find my notes on it
ok
I think the parent exponential function is f(x) = a^x?
And all exponential functions pass through (0,1) because a^0 is always 1
a is apparently the indicator for whether or not the function slopes upward or not
5=5
log_e(x) = ln(x)
Continuous growth formula
see i would say e is useful for exponential growth but you dont necesarily need e you just need exponent lol
but its better to work with π
if you differentiate e^x you get e^x 
Very useful
indeed
I'm not sure i'll ever understand what difference it makes
because if e^x = ln(x), which is another form of logarithms, and logarithms are inverse of f(x) = a^x, then wouldn't e^x be the same as f(x) = a^x?
But even then it still begs the question of practical usage
do you know what a derivative is
π
Doesn't sound familiar
i really can't think something that specifically uses e without calculus

something that practically uses e and has to use e (like can't really bypass it)
like exponential growth sure but you can just use f(x) = a^x
π
doesn't have to be a=e
btw uh
f(x) = a^x
is just a general parent exponential function
f(x) = e^x
is like very commonly used exponential function, usually what people/I think of when they/I hear "exponential function"
f(x) = a^x
since a = e^ln(a)
f(x) = e^[ln(a)x]
if you replace ln(a) with c, because both are arbitrary constants, u get
f(x) = e^(cx)
so really a^x = e^(cx), they are related
π
e comes from compound interest, but it has really nice properties in calculus which is what makes it so important
huh
thanks
are you familiar with the problem where you just have a rectangular grid?
if so, extend the figure in part a to a rectangular grid
count the number of ways which pass through the top right corner and the point below it
multiply by 2
then do total ways - previous answer
seems like you might need generating functions for the other two
the other two are pretty insane
or you know just count how many ways there are to get to each intersection point
Callisto(Moon)
How do i put this in terms of sin(x)
lets try to see if turning everything in terms of sin and cos work
Ok let me try
I got
$\frac{cos(x)}{cos(x)(sen(x)+cos(x))}+\frac{cos(x)}{sen(x)(sen(x)+cos(x))}$
Callisto(Moon)
take the lcm
and see if stuff cancels out
Om thanks
What does he want?
Am I supposed to be punished for this
it looks like a magnetic field lol.

pretty sure its just the unit circle π
nuhnuh, i see those vectors going from one point to the next
theres no arrow so u dont know which direction the vectors are going in 
plus thats a dotted line not vectors
that reminds me of the graph on my mic's packing
decibels/angle or sth
It's the polar coordinate system
At least it was intended to be so
The graph of the equation was actually a perfect circle
same thing just without unit 
Could someone explain to me why its -14 and not -13 because I'm pretty sure -34+21 is -13
,calc (5.81)(1.67)
Result:
9.7027
9.7027 > 6.626 hence when you divide 6.626/9.7027 itβll be < 1
Well it says the correct answer is 6.83 its just saying I got it wrong because I had 10^-13 instead of 10^-14
^
,calc (6.626)/((1.67)(5.81))
Result:
0.68290269718738
hi
Hi
isn't there a way to do that question using combinations?
for b and c you've got to be kidding me
for a it is possible and that is what I have suggested
I see
im cooked for this lmao
they also said you can use binomial theorem for it
which I have no clue how
but i'll get it
but actually just do this
it's not worth doing something super convoluted
got it, thx
hey guys how i calculate this function f(x) = -xΒ² + 7x + 12 ? Cause the square root of delta is not exact
my delta is = 97
,calc 7^2 - 4(-1)(12)
Result:
97
it is exact!
the solution is just to leave the sqrt(97) as a square root
don't try and write it as a decimal or it won't be exact
how did you call this?
discriminant
$x = \frac{-7 \pm \sqrt{97}}{-2}$
south
you were missing the plusminus
i mean the bot but okay lol
oh LaTeX
ah okkkk
Β°
One of the greatest motivating forces for Donald Knuth when he began developing the original TeX system was to create something that allowed simple construction of mathematical formulae, while it looking professional when printed. The fact that he succeeded was most probably why TeX (and later on, LaTeX) became so popular within the scientific...
yeah i was trying to type it
now how i calculate this thing?
just stay there?
oh you are going to have to round your answer
but we can still calculate those roots
ok
,calc (-7 + sqrt(97))/-2
Result:
-1.4244289008981
,calc (-7 - sqrt(97))/-2
Result:
8.4244289008981
there
,w -x^2 + 7x + 12 = 0
cause my book is tell me the answer is 3 or 4
are you sure it's not x^2 + 7x + 12 = 0
'-'
yeah you wrote the question wrong
this factorises as (x + 3)(x + 4) = 0, so x = -3, -4
multiply both sides of -x^2 + 7x - 12 = 0 by -1
hm okay
yeah it worked
is just because of 12
i accidentaly changed the sinal
signal
idk
hey lads just asking, i've been trying to find a book of excercises for Non-linear system of equations (i think thats what its called translated, the ones with more than two equations which equals a certain variable) (the ones that you learn in algebra), and for the life of me i cannot find them, anyone have a suggestion?
most books i've checked only has linear equations
Can u ask for help here?
yes
the 1st question should have a white circle at (1, -2)
sorry at x = 1 there is a removable discontinuity
with the 2nd function, continuous at x = 0
How would you prove that using continuity tests thoβ¦
you need to check that the left hand and right hand limits are equal to each other
but also that the the limit equals the actual value of the function at the point
So f(1) =-2
the question is broken
I assume they mean f(1) = 0
even though the limit exists and equals -2
Can someone help me understand how the 2 became negative in this?
The original question is h(x)=2x-xΒ²
2*(-x)=(-2)*x=-2x
Ohhh so you just removed the functions and timed them together.. makes sense tysm
is there any seperate # for calculus like differentiation or integration etc for jee mains or advanced level
this server does not have channels dedicated to any particular examination
is anyone able to help me with this problem been struggling with it
I mean even after looking at algebra books, they still only have Linear System of equations, not Nonlinear
"the ones with more than two equations which equals a certain variable"
are you thinking of linear systems of equations with 3 unknowns and 3 equations? or do you actually mean a nonlinear system
In thai it's translated as Nonlinear, maybe I wrote my explanation wrong
It's more of like
2equations with 2 unknowns
With 2 variables
like
5x+4y = 6
4x + 3y = 2
this?
Yes
that is a linear system of equations, did you look through the book content or only at the titles?
I've looked at the book contents as well
strange
I've went from JEE exercises to God knows what
i feel like the majority if not all algebra books should have it...
why are you doing regular linear algebraic systems of equations?
π
No I'm doing it because my teacher has asked me to find him a book with exercises so he can teach the kids a little better
oh
I mean we have them in thai, but it only contains like 60ish questions
Actually I have the PDF why don't I just send it bruh
Here something like this
can someone help me please?
No calculus channel available to me so I'll put it here
The function p represents the profit per item sold, where x is price sold for, a is the production cost, and y is the profit per item
p(x)=x-a
The function c is used to model the amount of customers and how the amount of customers decays as the price increases, where x is price the item is sold for, b is the total market, and m is the percent decay per dollar of price increased, and y is the amount of customers.
c(x)= bm^x
Given these variables, when, in terms of the given variables, will the total profit be maximized
-> cos wave amplitude is now 1/2
-> Period is now pi
Start from 0, 0.5 and sketch key points
The next key point is pi/4, 0
I have a question, after we find possible zeros of a polynomial function with [p/q] , do we have a choice of using synthetic or long division to find the rest of the real zeros or only one can work?
Wdym
Use synthetic division for all your zeroes and check - if one works, use the quotient to do synthetic division
like this for example
do we have a choice of using long division if we dont wanna do synthetic?
Yes
But synthetic is faster
IMO
Same
Takes up half the paper, and is weird
guys can someone tell how to cover parabola, ellipse and hyperbola in the least possible time π?
Ask the chat gpt bot that is good at teaching
bruh wattπ₯
!nogpt
Please do not trust ChatGPT or similar AI tools for mathematical tasks, as they often generate output which "sounds correct" but has numerous factual or logical errors. Use of these AI tools to answer other people's help questions is strictly against server rules (see #rules).
hey guys
i need help with this
Find the values of m for which the function f(x) = mxΒ² + (m + 1)x + (m + 1) has a double real root.
my last answer was delta = -3m +1 -4mΒ² π
i'm not expert in math but i think was is not right
nvm guys
i find the answer lol
If you want to cover it in the least possible time then dont learn much
Does anyone know where x went? I know it took x as a common factor but in the beginning it had x^2, shouldnt x^1 remain?
oh wait
yeah that's clearly a misprint
,w (d/dx (cos 2x)/x^2) - (-2x sin(2x) - 2 cos(2x))/x^3
other than the misprint it's correct
Thank you!!!
That just means discriminant = 0
Sub the valuea
how do i start out with calculus. Like i know limits and stuff. Trigonometry is done, im good with algebra and graphs
https://tutorial.math.lamar.edu/Classes/CalcI/CalcI.aspx - these are really good
Here is a set of notes used by Paul Dawkins to teach his Calculus I course at Lamar University. Included are detailed discussions of Limits (Properties, Computing, One-sided, Limits at Infinity, Continuity), Derivatives (Basic Formulas, Product/Quotient/Chain Rules L'Hospitals Rule, Increasing/Decreasing/Concave Up/Concave Down, Related Rates, ...
yes then you should start by learning the rules for differentiation
sum rule and constant multiple rule
then product rule, quotient rule, and chain rule
i know some of these rules
no worries!
How do I graph these log functions?
Thank u
anyone have any good recommendations for a good precalc textbook
Axler's Algebra and Trigonometry
or Axler's Precalculus
they both cover the same material but this is more detailed
soygpt
ok thanks
Axler is the goat
But like the front of the AP Calc BC book is where I learned most of my precalc (the review portion)
pretty much brand new to logarithms right now and im lowkey lost at this part. I got up to here but dont know where to go next.
got cut out in the picture but the packet says to use the natural log
i have no idea if im even doing it right rn
You applied the right rules but there is a step where you could have isolated x
And then if you wanted to, the denominator simplifies to ln(0.6) as well
alternatively, $5^{(\log_5 3)x} = 5^{x + 2}$
$(\log_5 3) x - x = 2 \implies x = \frac{2}{\log_5 3 - 1}$
south
same thing by change of base rule
Could someone provide a correction? I'm unsure about my answer because my teacher said it was wrong.
it's correct. so it may be that your teacher wants you to justify it in some different way, in which case you would have to ask your teacher directly
I really appreciate it!
Plug in some values you think would make whole numbers by matching the argument to powers of the base
that's not what the change of base rule says
order of operations is super important
say you wouldn't think $\log_{16} 32 = \log \frac{32}{16} = \log 2$
when it's really $\frac{\log 32}{\log 16} = \frac{5 \log 2}{4 \log 2} = \frac{5}{4}$
south
the biggest difference is that the first one is still a logarithm
when 16 and 32 are related by powers of 2 so you should have a fraction
which answer choice would it be
it's not A
choose another answer choice and I'll tell you if it's right
d
yeah it's D
thanks
π
Yβall how is this not one to one?
I understand from the graph of it bc of the horizontal line test, but still I canβt figure out how in the equation way
oh it's cause $(x_1)^2 = (x_2)^2$ does not imply just $x_1 = x_2$
south
you could also have $x_1 = -x_2$
south
that's what they mean
can i get it for free online?
lol I was joking
But like yeah most resources are free
The university of Waterloo also has most of its pre calculus courses online
i'll check it out, thanks anyway
Np
Is this some high school or precalc channel or university precalc channel?
I am just wondering cause I may need help with sketching a trigonmetric wave
there isn't enough of a distinction between "high school precalc" and "university precalc" to have separate channels, so this covers both
Ahh ic
Where we live, Uni precalc doesnβt exist
Most precalc is taught in high school
I have given this sinus function: in the form f(x)=a*sin(bx+c)+d
I have to determine all the parameters:
a=1
c=0
d=0
I am stuck with b . I cant figure out. how long the funtion takes for one cycle. anyone got an idea?
for sin to be 2 pi whats x?
after you get that value you get the answer
here sin is one at pi/4 so its reaching its peak at half the x expected so b would be 2
without b cycle cant be identified
hi
how would i do this without having a unit circle handy
or memorized
can i plug sin 1/2 into my calc to get these or what
if sin(x) = 1/2, you know that one value of x = arcsin(1/2). Similarly, sin(x) passes 1/2 two times per period. not sure how you would do this part without the circle, but the other value per period is pi - arcsin(1/2). Anyway, then since sine has a period of 2pi, you know that the two solutions are x = arcsin(1/2) + 2pi n and x=pi-arcssin(1/2) + 2pi n for every value of n. But now I just realized most calculators will calculate arcsin(1/2) as an approximate answer instead of an exact answer in terms of pi.
honestly i would just try to know the unit circle bre π
I think itβs best to memorize the unit circle tbh
Although scientific calculators have an inverse sin function, which can be used for finding x in that equation (for that question, calculator mode MUST be in Radians mode and not Degrees mode because the value in the given equation is not written in degrees ), the calculator is going to give an exact value in degrees for x, which is: 30. However, it will not give the other correct value , which is 150.
Which is why I think itβs best to know or memorize the unit circle because 30 is not the only answer for that question
ahhhh im cooked i got a test tmrw π
I saw this on TikTok
this is for the sine and cosine values of these 5 angles: 0, 30, 45, 60, and 90
I still think memorizing the unit circle is easier tho βcause thatβs what I did when I was in high school π«
ahhh tyvm
i heard it was a good dea to memorize it
but i never took it seriously LOL i see why i should have now
YO
can someone help me with my study guide and walk me throug hit
a call would be nice i also made a forum in the #1021175428326633542 #1315516203128590497 it has my study guide on there if someone can come help me much appreciated
Is the only way to prove this identity is to assume it is true and then combine the two to see if they undo each other?
Plus what is that kind of proof called?
define $f \circ g \circ \ell = h$ then by definition $h^{-1}$ is the function such that $(h \circ h^{-1})(x) = (h^{-1} \circ h)(x) = x$
cloud
so to prove that h^{-1} is given by a certain formula you just need to show the formula follows that definition
Calculator says what
help me please number 7
Imma be taking this class during my winter semester, what do you guys think i should have do to prepare myself for the class?
hey'
could anyone help me with continuous fourier series and transforms?
i kind off have my test
you should probably ask in #odes-and-pdes instead, and post a specific question so people know what you want help on
thank u
Do half of the course online somewhere like khan academy
then you wont struggle with bad grades if thats what your worried abut
Yeah thats my main concern
I dont want anything lower than a B
What grade are you in
Wonβt matter if itβs senior, although you being here means most likely your not a senior
why
That's actually genius ngl
Wonβt go towards college apps
actually, you can do it with just one hand
I don't remember how to solve this, but i remember it being very simple
seems like it was something like . . . I(20) = x?
they can still decline you even if you get accepted if they dont like your grades for last sem
Really? My whole school, no county ig I could say just donβt care about their last year grades
I donβt really know however so I canβt be sure
I feel like this is just asking for the inverse.
Am i wrong?
yes, its asking you to graph the inverse
what about it?
40/3 yea
I think it's how much money 20 comes will cost
Since it's the inverse
if you want to do it the function way then let $a = I^{-1} (20)$
hence $I(a) = I(I^{-1} (20)) = 20$
in fact $I(I^{-1} (x)) = x$ for all $x$
south
since I(x) is the number of ice cream cones, number of ice cream cones = 20
yeah this is confusing
easier would be to note that I(x) has:
input = number of dollars, output = number of cones
hence I^(-1) (x) has:
input = number of cones, output = number of dollars
number of dollars for 20 cones
I^-1 mean I inverse
I^-1(20) outputs a number for the input of I when the output of I is 20
Oh yeah south explained it better
Also @sharp nova important note f^-1 or f inverse β (f)^-6
So if you have the function f(x)=x f(6) would equal 6
But f^-1(6) wouldn't be 6^-1 or 1/6
I have a question and I'm getting contradicting answers, idk if this is where I ask. However my dilemma is when performing the transformation g(x) = f(2(x+1)) would you shift to the left one or compress it first
HUH?
I didn't realize that this worked on logarithms as well
i thought it was just exponents with the same bases
No one except yourself knows what the "this" you're referring to is
sorry, using the one-to-one property to solve for x in logarithmic equations
apparently if you just have two logarithms you can just. . . discount them from the rest of the equation?
and solve using just the arguments inside?
Yes
I know you can do the same with exponents, an example being
3^2x-5 = 3^7+4
and rewrite as
2x-5 = 7+4
This is because the logarithm is an injective function
I.e. it has an inverse
You can see it as raising the base of the logarithm to the power of either of the sides
Do it in the order listed
In the question
well exponents of the same bases and logarithms are inverse functions, so the fact that one is invertible implies the other
Logarithms are invertible by definition as well
i need help understanding how f^-1(x) works on a graph
so i have a question which is "give the domain of g^-1(x)" and the graph that it gives me is g(x)=2arcsin(x)
is the domain [-pi,pi]
the domain of the inverse function is the range of the original function
multiply and divide with $1- sin \theta$
π€―
The conjugate okay thanks
Can you walk me throgu number 63
Busy rn sorry
Oh pk all good
How would I do 3c? How would I expand it ( the rhs) or...
LHS = (cos x cos y)^2 - (sin x sin y)^2
Then try to factorise or something
can someone help me, when im creating a piecewise function from an abs value function, how do i find the domains of the piecewise function
this is an example of what im talking about the yellow highlight part, how do i determine that part
because ive tried setting the piecewise in the same format greater than equal to/greater than/ lessthan equal to/less than to 0 but it doesnt work
that's just the definition of $y = |x|$
south
$x$ if $x \ge 0$ and $-x$ if $x < 0$
now replace $x \mapsto x - 3$, everywhere that $x$ appears
south
thank you
the other definition is $|x| := \sqrt{x^2}$
south
that may be even more unintuitive
try choosing a positive x and a negative x to see how it works
np!
help.
<@&286206848099549185>
The question asks for 10 terms. Start with 2, 3 terms and see if you can find a pattern.
could anyone please help me with simple induction? i dont understand the last step in proving the IH and IG and where to sub them into the formula
!help
To ask for mathematics help on this server, please open your own help channel or help thread. See #βhow-to-get-help for instructions.
Just substitute ri8
Thx so much Natalie
yw π
hi, i need help with this math problem
i need to find the values of x in which that is correct
this is the answer btw
For the base you have that x-3>0 and cant be 1 so x=/=4. For the inside the log it must be x^2-4x+3>0
why > 0?
Which one?
Definition
it cant be zero
Yep
and the same for the base aswell
it must be > 0, thank you
and can you help with number 9? We must find the smallest whole number for which that is true
i dont know what to do with the 2x - 3 in the log
simplify that 3^(2log...) instead
Write a function named f which fofof(x) = x
f should be a reciprocal function [(ax+b)/(cx+d)]
anyone have an idea ?
no, i did that, but then what? I got to the point where its 2log(2x-3) <= 8
and dont know what to do from there
divide by 2 first
yea?
and then 4=log_2(16)
hmm something is wrong
im getting this as an answer
and we are trying to find the smallest whole number that is an answer to it
in this case its 5, but in the answers its 2
just solve 2x-3>0
oh my god when i flipped the 3 to the other side i wrote it as a nine π€¦ββοΈπ€¦ββοΈπ€¦ββοΈ
im really sleepy, sorry
and is it possible that there are more than one logs with variables in them?
everything is possible in this world
yea but i can only derive that they must be > 0
and i dont think thats enough to solve it(?)
depends on the problem
ill just hope i dont come across such a thing, thank you so much though
I could use some help with non right triangles
I've never got this concept but why is sum from k=1 to n of a_n =na_n
Why? Math is fun
I doubt the person you're replying to thinks math is as fun as you do.
trust, math is fun
Just gotta look in the right places
hello im having trouble with this study guide my teacher gave me im not sure what to do from here:
i took the natual log on both sides but an unsure how to simplify it from here
i ended up finding a solution that is easier for me, doing sign checks yay
i think before u take the natural log of both sides u should make both sides have the same base so i would simplify this to 5^3x = 5^-2
and then try simplifying from there
u can review these properties as well to study
ngl i personally would just use same base rules
also are there specific scenarios where you have to use ln?
if so please explain
would the answer to the question change based on me using ln and base log?
talking about this
ln is more simple for me imo
and also i gotta think about this question lol
why not just take log base 5 of each side?
whats the difference between ln and e?
that might take longer
ln is basically log base e of something
if you take the log base 5 of each side u would still ahve to simplify it anyways
so why not just do it all in one step
whats difference between ln and log like when you use them, does it make a difference?
i personally would just convert each side to apower of 5 and use same base rules
cuz thats sooo much easier
i think thats what i said to do
"i think before u take the natural log of both sides u should make both sides have the same base so i would simplify this to 5^3x = 5^-2 "
thats what i said earlier
oh yea
you coulda just replied to it lmao
i have a test on all of this tommorow π
im deadass studying what a log is
am i cooked
wait
mods
sorry i thought u were trying to learn
i am
i got a 69 percent on my last quiz
i have my math final tomorrow dont worry
failed but 1 point π
im prettyh sure i was supposed to get 50% on my test but my teacher curved it so much it ended up as an 80%
cuz the teacher changed it from out of 80 to out of 40 points
π
bro on a spanish test i lost 8/10 points and got a 100
dang
oof
but its mb for sleeping in that class
π lucky
on a physics test i got a 50 percent with extra credit π
i heard physics is realy hard
yea
how are u taking physics as a freshman
im taking it as an ap too
ok how
its like the program at the school i attend
its mandatory
so does everyoone learn physics early then?
yea
oh thats odd
theres 48 people and all of us learn ap physics first
why do u learn all the aps first
no we take all the science classes
at my school u have to take the honors class first b4 taking the ap class
so for example freshman i took honors bio, next year i had ap bio and honors chem
what year you in?
that sucks
sophmore?
yes
damn
what
you taking pre-calc?
im tryna take bc and physics c (physics 1 with calc) by junior year (both ap)
ehh kinda
if i just worked harder i probably could have an A rn
oh so is bc just faster learning pace then
basically
and harder too
if you take bc then you might be able to calc 3 (3d calc) if your school offers it
bc doesnt cover all of calc 2
you should probably take a dc calc 2 class before doing calc 3 at school assuming no prior experience
i think after ap calculus bc for us its multivariable calculus
its different for us tho
im not sure if we take linear algebra or multivarialbe after bc but its one of those
idk bro
its your school
aight gotta lock in
ttyl some day in the future?
yea
for sure
ok same lol
yeah
im going to try to stay off discord for 2 hours challenge
cya
What would base level precalculus look like?
Limits derivatives is what im learning rn
that's moreso in preparation of calculus
Its just calc 1 isnt it π
Not really preparations
yes thats why im saying its just in preparation for calc 1 at that point
True
Oh so then precalc would probably be something like trig related?
I kinda thought that was review of alg 2
it was like linear and angular velocity
precalc is review of algebra 1, 2, and introductory trig and sometims calc yea
Oh ok
can someone take a short look at this pdf and give me recommendations for more practice questions?
wait this pdf doesnt work let me get a different one
here are screenshots i would really appreciate it if someone could find any more practice questions i can do liek these questions
Does anyone know if the answer is a or C? Cus on chatgpt it says C but my question bank answer key says its A (but sometimes it puts the wrong answers to trick students on purpose)
A is correct
time to use commands 
Please do not trust ChatGPT or similar AI tools for mathematical tasks, as they often generate output which "sounds correct" but has numerous factual or logical errors. Use of these AI tools to answer other people's help questions is strictly against server rules (see #rules).
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.
But he asked whether a or c , so I assumed that he got A and just confirming !
sorry
Ok so can u tell yr process if u are not confirmed with yr answer
Hello, i'm working on a demonstration right now, and i needed to use summations(not sure of the term) but i'm not sure on how it works with funtions(i'm using wikipedia and they don't develop much further than just that you can use them in summation)
Does anyone know where i could learn how to use summation with functions?
(Is this the right chat)
I'm not sure what you mean by summation with functions
I'll try to take a screen shot of the thing
Something like this: $\sum_{i=3} f(i)$?
daniel
So what is your issue?
I'm just wondering how do i write the rest, like after
As in what it's equal?
Yeah
That example I posted is just $f(3) + f(4) + f(5) + \dots$
daniel
Hey uhh I need help understanding system of equations with and without substitution and process of elimination
In word problems
And for like the sum of all number in between two other number(such as 2 and 3)
?
Then it's f(2) + f(3)
I meant more like in between those number,
If it's from $k$ to $n$ it's $f(k)+f(k+1)+f(k+2)+\dots+f(n-1)+f(n)$
With like 2.3
daniel
You can't use non integers in sums
It's always integers
I studied so hard for my precalc test and this test I found it so easy it is geninually concerning for me as I don't usually find math a strong point for me
Because I don't usually feel as confident like I did on that test

you can really only use these two
Anyone have strategies for graphing these functions?
It aint fun when I start learning calculus.
Get the estimated values for f and g on the graph then use those values in the other function for example
Letβs say I have a graph the says the f value that equals 1 and g value that equals 2
Letβs take (f+g)(x)
We can add the f and g values together
guys i know grade 6 to 8 maths geometry algebra and trigonometry form youtube should i start learning precalculus??
yes
Why not, but I would also make sure you know deep into algebra very well first
Not like knowing the y values of each x value BUT knowing an easier way to graph each functionβs section
In that case idk
look at the behavior of the graphs
for example g(x) has a larger negative value around the left of the graph, while f has a smaller value, and they both grow in size which means if you were to add them together the value would be large negative and then eventually grow to positive
also not sure if this is going to help but these were the notes from my lecture that might be related
Hey if a function can algebraically be switched with the x and y and coefficients moved to the x side than is it a inverse thats all thete is to it?
inverse on what domain is a question worth considering
Hey can you pls walk me through this i must be dumb or smth
Nimber 14
is there a command to rotate the image...
π€―
the swimming pool is 8 feet longer than it is wide.
let w represent the width of the pool: the length of the pool is (w+8)
the pool is surrounded by a walkway of width four feet. the combined area of the pool and the walkway is 1280 ftΒ³
if the walkway has a width of 4 feet, then we can find its dimensions including the pool by adding 4*2 to the width and length of the pool, so the area of the walkway and pool combined are (w+8)(w+16).
set this equal to 1280 and solve
(w+8)(w+16) = 1280
wish i could draw...
Would you add 4 twice to each measurement since 4 extends all around
me too lol
Actually, calculus is overhyped. But if it's not your thing, I respect that
u need to check after u get y by itself again by plugging either the inverse function into the original or the original into the inverse, if you get x then it is the inverse function,
also you can check using the horizontal line test on the original, if the function touches the horizontal line more than once that means its inverse function is not a function
,rccw
Couldn't find an attached image in the last 10 messages.
,rccw
,rccw
,rccw
perfect
Is it wise to leave the conic sections for calculus itself rather than taking it during precalculus?
I've just checked and seen that Stewart's book has a section for conic sections, which doesn't really contain something that the section from the precalculus book doesn't.
So it appears like this is indeed an option
I would just do whatever your class does. Are you self-studying?
Yep
What's in the conic section part of your precalculus book
"Rotation of axis" confuses me though. I can't see it in the index of Stewart's
Don't worry about it
So it's covered?
It won't prevent you from learning calculus
