#precalculus
1 messages · Page 55 of 1
No
@silk dew
Ok
I have to do all this ?
Yess
They are
But why u asking calculus in precalculus group ?
#calculus go to this
Yeahh, bring that to calc
which ones
Q4
I asked but no body helped
Yes
is the answr = e
this is actually not an integral question
Did u used Limits?
it is more like of a limit
No reason
Yes
I have some more questions would u like to try out urself
people here
yes buddy i will help u
dm me
Oh
u which class ?
i do not think i am doing the right thing here
Should I give u a hint?
I proved it though
sure
First convert them into sin and cos
Then take the common term 1/(sinA-cosA).
I'll leave u from here
i got it, thank you
guys can someone give me an equation of a hyperbola
(x^2 / a^2) - (y^2/b^2) = 1
xy=c also comes under a hyperbola
rectangular hyperbola
how do we solve question 24? i am getting cos(A)/[1+sin(A)] = [1-sin(A)]/cos(A) but i do not know how to proceed further
Here's a hint, start from RHS
Separate the terms
And try to use the formula a² - b² in a way.
in LHS?
but does not it just become secA-tanA
It becomes secA - TanA after separating right?
yeah
Now multiply SecA + TanA both in numerator and denominator and try to remember a relation between sec and tan
Should I tell u the solution?
Ok tell me what are you getting after multiplying secA + tanA?
1/(secA+tanA)
There u go
thank you
of what level is it, though?
I don't know I have never done it lol. I have seen it's questions but
I tell u it's better for the practice
one of many historical "special functions" that were used before the advent of calculators, because it was useful to be able to read them out from tables
covers, vers 
ancient trigonometry
How do we prove that polynomial functions of degree 2 or higher don't have "sharp corners?"
Additionally, why aren't polynomial functions of degree 0 and 1 considered as "smooth," unlike those of degree 2 or higher?
Oh wait, by "smooth" we mean a function whose graph only contains rounded curves
Ignore the second question
pray
its probably some trig identities mixed with partial fractions or something idk
why is r=3
what is r
great advice, thank you
we do not see an r
how do I proceed further? got it
if we are given that perpendicular + base = hypotenuse in a triangle, what can we interpret from it?
if that is even possible
i cannot think of values that satisfy that
Question. With Horizontal Asympotes, why're you able to cross the HA in some cases?
why do you think it shouldn't be possible?
the definition of horizontal asymptote isn't that it's a line that the graph of a function approaches and never crosses
It can only be possible if all the three vertices lie on the same line, i.e, they are basically collinear points.
The sum of any two sides of a triangle is always greater than the third side.
right
I am in confusion that what should I do first calculus or stats / prob
why are you confused?
both are perfectly valid options
depending on what you want to do
calc
Would yall say this is easy/ easy to study ?
I have an exam on this entire portion, do yall think a week is enough to ace it?
yes but depends on your level of algebra
Idk what that means but we can’t use calculators 😭and the way they teach math here is terrible in high school
This is college btw,
like, what algebra have you learned so far?
but thanks for telling me that info
I bet Khan Academy can help you with most of these topics if you want to practice
easy peasy chingling cheesy
I don’t really know their names but I’d say maybe a very small amount, idk what algebra really means if I’m being honest they straight up never explained mathematical branches it was just “math”
But I’d assume I know a tiny
so then these chapters would be new to you in some way
either you don't know them at all
or you've forgotten how to do certain things
hmmm there's a lot online and in various secondary school curriculums
Khan Academy as I said
Why is this limit equal to 0?
maybe try LH on ln(e + 1/x) / (1/x)
Tysm this is great help 🤍
no worries!
also I can't send this here, but James Stewart's Precalculus
you can get an older edition like the 7th edition online
Stewart’s Algebra and Trigonometry is basically the same book as his precalculus. Buy used. But these are like big books. I have Stewart - brilliant. But Sheldon Axler’s Precalculus is shorter and better, I think. Cuts to the chase.
Oh, and Axler book includes the complete solutions manual!
Wordle 1,220 2/6
🟨⬛🟨⬛🟨
🟩🟩🟩🟩🟩
this becomes x ln(ex+1) - xlnx
the 2nd part is just zero
focus on xln(ex+1)
plug zero in
0 * ln(1) = 0^2 = 0
My brother, what is a "chingling cheesy"
you dont know chingling cheesy??? :O
hOw CoUlD YoU
he is the greatest mathematician ever lived
tbh ye it is
Checking in, how much progress have you made?
None
It’s in 2 weeks
And a lil more
so it’s not 1 week left planning to start soon
You better start right now
I’m hella tired today might start tmrw
fair enough
Also lowkey I’m scared of studying math for some reason
it's very easy
Should I just solve examples non stop?
ur cooked
My issue is I solve a few examples a few days before the exam
personally i would give up
bro 💀
Wtf?
dont listen to him
Bro this is hella short material
u should give up
And I have 2 weeks and a half
and sleep
anyways @upbeat yarrow for DEs what year PYQs should I solve?
des 2022 and 2023 mains some exact differential questions were pretty annoying
iirc
what abt 2021 and 2020
i dont remeber
Sakura pfp
bad memory
Why did she lowkey carry Naruto
okay im gonna go and solve 2020-23
yes
FRR
.
didn't watch naruto ever
L
Makes sense
I remember binging entire shipuden in middle school, was cozy and fun tbh
In the derivation of the remainder theorem, we are setting the divisor (x-c) equal to 0 (c-c). How can this be working considering that the divisor is in the denominator before we manipulate the equation to get the division algorithm?
I dont got paper near me
But i ln everything that undid the left side so i have now 10x-7x=ln-2
Than 3x/3-> ln-2/3
real valued log is only defined for positive numbers
I know what you did but you can’t do it directly that way cause it gives you something undefined
Get it in thr form of a quadratic and then factor it
I feel like this wiuld be rlly easy but idk how to do it
you want to split it into two separate rectangles and then add the area of both
can you give me the equation im confused
A = ((3x+4)-(x+1)) (2x+1) + (x+1) (x+1)
the answer key is 5x2+10x+4 idk how u get 5x^2
What are you getting?
im getting brain damage
Do you understand this image @rocky whale
yea but idk what the equation is saying

ah, the first part of the equation is calculating the area of the left rectangle
so that's the (3x+4)-(x+1)) (2x+1) part
and the second half is adding on the area of the right rectangle
which is the + (x+1) (x+1) part
does that make more sense?
yea
not sure if you need this anymore but this is essentially you’d do that, i just skipped straight to imputing variables into the last part instead of breaking it down
thanks mane
ur carrying me
w
my friend says i love you
👍
guys
Cant tell if you got an answer or not?
Hello, guys
Are there any "smart" ways of solving it without considering all the cases?
guessing 
think about which combinations of cases are possible. that narrows down the amount of cases you have to consider
Hmm, whenever I see modulus, I do combinations type things
First case all modulus positive
Secondcase first two positive third negative
Third case first positive second negative third positive
Fourth case first positive rest negative
Etc
Ul get 8 cases
Solve em find the common intersection
I believe you can reduce it to just 4 (=3 + 1) cases:
- x ≤ -2
- -2 < x ≤ 0
- 0 < x ≤ 2
- x > 2
Oh ok thank you
plot it
I understand how to factor everything in magenta, but how do I determine the cyan part?
Like where does it come from
I know why it’s there, it allows you to fully factor the thing, but how did they determine that +4x^2 and -4x^2 was needed specifically?
wait so like
There’s no rule??
Because I can use the diamond solver trick thing to find -4x and -15x easily
But I have to guess for the 4s?
how can we divide x^3-3x^2+3x-1 by x^n?
n>3?
it's not given
You cant do that without a remainder
Youre dividing x^n by x^3-3x^2+3x-1 not the other way around
And uh im not sure if you know the trick for the f(x) part
But its like let it = ax^2+bx+c
And sub x =1 on both sides
Repeat
After differentiating
why?
And repeat again after differentiating
Then you get the values of a,b,c
Tho im not sure how you would get the g(x)
Because the degree of remainder of any polynomial is always less than the degree of division
why diff?
What else can you think of?
That was what i was taught
So yea
Thoo if you have another method id really like to hear it
Cuz this one quite frankly is a pain
Does this trick have a name? I'm not doubting you, I just want to know the reason behind this
I mean when i was taught it this just came under an example to the remainder theorem
Maybe it does have a name
Im not sure
I mean like, why diff it suddenly?
Gotta do what you gotta do
Sure it was counterintuitive to me too
But well
If nothing else works
hello
specifically b
i have a quiz today and i don’t understand this
it wont send nvm
✨
the hins is sin(3x) = sin(x+2x)
wait so to factor it ill tell. (4x^2 - 15) ( x - 1)
trying to help someone with precalc, it gave them this sequence, and i said that the sequence could be represented as
$a_n = 2^{-2 + 5 floor(\frac{n}{6})}$, but the values in the screenshot (correct answer) make no sense to either of us
Alrighty
The floor thing doesnt work
It clearly says the func is of the form a* b^x
And not a * b^(g(x))
So that just implies the que has some error
There's none
elaborate
No x satisfies 1/(x^2) = 0
,w roots of x^(-2)
See
cuz ur dividing 1
the lowest u can get is 0.000000000......1
infinity zeroes but theres 1 at the end
but still > 0
For a graphical demonstration
What shape is that
Graph of 1/x^2
At x = 0, y would be infinity but for some reason infinity is undefined so yea no solution, real or complex
Look at the values given in the function’s correct solutions though, how do they remotely make sense
is this the final answer or can i rewrite it as
4 sec(4x) tan(4x) ?
numerical coefficients are better written at the start
Are derivatives considered precalc?
Commutative and assosciative property of multiplication, you can put that 4 in the middle, in front, or at the end. Coefficients usually go in front though
i believe its basic calc
Yeah but trig derivatives usually aren’t intoduced in pre calculus
In my precalc we got the formal definition of a derivative
And that was it
They dont
That’s what I’m saying
So the question is wrong?
(Also ping when replying)
are conic sections taught in the us curriculum?
cuz it appears that in us they go straight to trigo and functions for precal..?
That is weird. In precalc, they usually teach only trig stuff
really
in my country precal was only conic sections then only do we slowly get introduced to trigo by the end of it
I replied to the person above. And yes, I think conic sections are also taught in the US
which makes me wonder that if u go straight to trig in precal, when do they teach conics?
damn so that could only mean
my country is far behind in math
I just realized my sentence was misleading there. I meant that they teach you trig and its properties, not trig derivative
And there is no standard for precalc curriculum either. It depends on your school I think. They might teach trig, conic sections, complex numbers, matrix, probability, ... there
its so interesting that people of the same age from different parts of the world could have very different levels of knowledge
Well, you will learn all of this more in-depth in college anyway
yeah thats good to know
im kinda scared for college cuz rn my only strong area is math
im so stupid at high school subjects other than math subjects like precal, stats and physics which are my strong forte lmao
Umm but precalc is math
yeah i would love to have math in college
Ok I misunderstood it 😂
im kinda leaning towards applied math or algebra but the dudes at #math-discussion got me rethinking it
i dont understand a single thing they talking about other than sigma symbol lmao
Then go for math major 
yeah i would love to go for math major but it seems to limit my career to be a teacher
which aint bad at all but teachers dont get paid what they deserve
Yeah. Can't argue with that. Becoming a math professor at a university is the only thing I know if I am a math major 
ur cooked
i know
Hi what does $x_{n+1}$ mean in $$x_{n+1} \leq x_{n}$$ and $$x_{n+1} \geq x_{n}$$?
wolly5114
the n+1'th term in a sequence
same thing
Yeah probably
When generating exponental regressions and using y^=ab^(x) do I have to also have a ^ over x (y^=ab^(x^))
what does that even mean
I think not because with regression you are trying to fit some curve over your datasets that is why you have y^ because it is just an approximation. But x is your input (not predicted x)
This is just a notation you can totally write y = ab^x but to distinguish between true y and predicted y, they usually write y and y^
Idk my teacher just taught it today and I have hw on it
Thanks
Can I use something like this to show that I want to find the y^ value for x=29. I'm 99.9% sure it's wrong but dont know how else I would write it
This looks fine to me. Why is it wrong?
Because it's not really a function just a equation for y^
My equation wasn't like y^(x)=. it was just y^=
It is a function, tho 
Well yes it can be written as one I guess
You are expressing y^ as a function of x
Ok I see
I mean technically it's a function but I haven't been using function notation
Thats probably the cause of the confusion
Yes that makes sense but I'm not sure my teacher would want that
I'll ask him
Thanks for help
math is vast
you can have different perceptions and solutions
but the final goal is to arrive at the correct answer
not always 😄
For horizontal aymptote
If the denominator has a bigger degree than the numerator than horizontal to is zero, but if the denominator is a smaller degree than the numerator than the horizontal is undef and if numerator and denominator are the same degree, then it’s a coefficient of the numerator over the coefficient of the denominator of the highest degree?
yea uve got the right idea, in general if the degree of the denominator is greater than the degree of the numerator then u get a horizontal asymptote at $y = 0$ bc as $x \to \pm \infty$, respectively the function will approach zero. if the degree of the denominator is less than that of the numerator then u dont get a horizontal asymptote as it is undefined, bc the function will continue to grow without a bound wether that be positively or negatively, as $x \to \pm \infty$, then our final case is if the denominator and numerator are equal then we get a situation where the horizontal asymptote it at $ y = \frac{C_{Num}}{C_{Den}}$ where $C_{Num}$ is the leading coefficient of the numerator and $C_{Den}$ is the leading coefficient of the denominator therefore we see that the horizontal asymptote is basicly the ratio of the coefficients, does that make sense?
emma
hi, does anyone know how to derive the formula sin(A+B) from cos(A-B) = cosAcosB+sinAsinB?
Yes thank you
For a logistic growth graph the denominator number to the right of the 1 is always just 1 below the carrying capacity limit factory (the numerator?
yes, it is whenever the initial value of y (at t=0) is 1
more generally you have this formula https://en.wikipedia.org/wiki/Logistic_function#In_ecology:_modeling_population_growth
in your case K is 5000 and P_0 is 1. The growth rate r is 0.8
I see thank you and is t a time value set in days?
depends on what your model describes; could be any unit of time
So it would needed to be multiplied or divided for hours or months
Oh ok
if it's some kind of word problem I'd check what it says, it should mention the time unit used
Guys help..
what have you tried so far?
it's in the form $y = k \frac{x - 3}{(x + 2)(x - 4}$ for some real $k$ btw
south's secret twin brother
Why do we integrate to find arc length
If integration gives us the area under the graph?
Try to read some of this
https://tutorial.math.lamar.edu/classes/calcii/arclength.aspx
In this section we’ll determine the length of a curve over a given interval.
Does anyone have practice problems for graphing polar functions on both rectangular and polar axes
if integration was only useful for finding areas we'd be doomed
the correct statement is integration is a general method for coming up with exact answers by summing infinitesimal quantities
i like to think of it as a continuous sum :>
if we add up the areas of very thin rectangles, we can get the area under a curve
nice analogy
similarly, if we add up very short line segments, we can find the arc length
Here is a set of practice problems to accompany the Polar Coordinates section of the Parametric Equations and Polar Coordinates chapter of the notes for Paul Dawkins Calculus II course at Lamar University.
try this
can we always separate the terms like this?
C + C + C + C = C(1+1+1+1)
how is that precalc 💀
I was studying that under height and distance
It is a sum. Look precalc enough 
everything is precalc 😁
💀
Really
Is everything in algebra 1, 2, and geometry used in calc
And am I doomed if idk proofs
no
actual proofs or just geometry proofs?
What’s the most important one used for pre calc?
you dont need to know those
most important what?
Yes
Out of the 3 subjects
those are kinda bull imo 😂
algebra 1 and 2 are mixed together for me, but more of those
Thanks!
What are actual proofs like

..
horrible 🤣
Oh
naw im just bad it lol XD
real analysis is literally calculus but proofy
you usually get like a proofs class and i think maybe a little experience in some linear algebra classes? and a LITTLE experience in calculus class
but real analysis is like very proofy calculus
Ohh😭 I see
calculus is fine but i would be so screwed if/when i would take real analysis ☠️
Is that its own Seperate subject
I mean....
what would you consider a seperate subject 💀
real analysis proves concepts from calculus
I assume they use concepts that aren't in calculus so theres that...
Like a course you take at school for a year
yes real analysis is its own course
I think learning new concepts and being able to apply them in different ways is key ngl
and also reviewing so you dont forget
idk why emojis go first when i put them after :l
How long do u need to review
Like
After you learn it
And then u move on to another thing
well the goal of reviewing is so you dont forget it XD
so you gotta think about what you know and be like "oh i kinda forgot that thing" and then go back to it
as long as it takes for you to not remember well, i don't have a set time 😂
it also probably depends on the topics
id say probably every few weeks, maybe a month idk its hard to generalize like that
of course if you know it you know it and you may remember it for like months or years without having to review lol
after a certain point it be like that
XD
Do you like math
yus
Do you like it even when you don’t understand it
And is ur brain ever too tired for math
uh
I like tryna understand it i guess?
i mean sometimes i make dumb mistakes so yeah 
Oh wow
Doesn’t your brain hurt tho
Like when you’re confused
And it feels like there’s a brick
And ur brain is glued
maybe if i was pressured to do it but i haven't been for a long time cuz i usually learn ahead n stuff 
if i need a break i take one lol
i feel like im not getting ENOUGH time to do math ngl
english sucks 💀
Usually learn ahead, like u learn before ur class
But isn’t that more confusing
I think my brain would hurt more
Good idea tho
I’ve been trying to do this for physics
no why would it be more confusing
Or else in class I’ll be so confused
Bc ur reading it without a teacher telling u
Idk
if i get it i get it
if i find something that makes sense 😂
O
I don’t ever
I always get things slower than my peers
But after I get it I think I get better than them
I love English
Jk I don’t
But I like writing
I never get tired of writing like I get tired of mathing
I’m so bad at analyzing work
i don't love or hate it, its just not my thing
hours and hours of not my thing
Mhm
rather than math, and the physics/cs i wanna learn 😭
But is hours and hours of math your thing
Physics is so painful
I can’t wait for chem
No
hey
any one has the book:
pre -calculus, by art of problem solving?
and can share the PDF for it?
Piracy isnt really allowed in here
But i hear someone named anna has an archive somewhere

I heard theres a library somewhere, think it was called genesis or something like that
Do you know How can i get to her?
Hello 👋🏼
I found the pdf of that book online !
If you want , I can send it to you via direct message !
no, dont ping me
ok
Hi could could use some urgent help… anyone active ?
whats the question
How do I write the equation for this graph?
Like I know (x-2)(x-4) will be in the numerator and (x+3)(x-4) in the numerator but what I don’t understand is how to find the a value. Do I just assume that the y intercept is -1.5??
if you multiply by a factor of 2 you should be good 💀
idk what the 'a' value is but
the limit approaching infinity of it has to be 2 because theres an asymptote at y=2
so it should have another factor of 2 in numerator
what do i need to start precalc
algebra i guess?
what part of algebra specifically
half of precalculus is just a repeat of algebra so just knowing algebra in general is recommended 
probably :>
its not that bad lol i wouldnt worry too much and just start :D
lol
how do we interpret this question
why have we taken angle QAP = theta and angle QBC = phi and not vice-versa? i get that tan(phi) is greater than tan(theta) but according to the first part of the question, should not it be the other way around?
because when i calculated it like that my answer was not matching
and like what if the question is in general form?
in second figure, how can we say that pq is the perpendicular?
this is the original problem
yeah the diagram is wrong
should be the other way around
take the distance b/w the points as 100 ig
wait its given 1
hm
QAB should be 30 and QBP should be 60
cause 60 is greater than 30 so it should be closer to P
also what have you done in the top right?
this is 3d
gotta visualise it
practice 10-20 questions and youll get an idea
it's a formula
for that particular type of question, H = asin(alpha)sin(beta).cosec(beta-alpha); beta > alpha
i am still not getting an answer
it's [2]
meh
i am running on two hours of sleep
i know
i am just pretty scared lmao
my goal was to complete trigonometry by the end of october and i am two topics behind
practice questions of height and distance and inverse trigonometric functions
Doable enough
how do I get to understand trigonometric substitutions
still #calculus lol
if u mean trig sub for integrals
ok thank u
cancel (x-7) and (x+2) out
practice
we have to calculate the value of n
i don't know what have I done but can someone please check my work
How did that partial fraction ended up as the bottom fraction?
where did that second fraction from the bottom come from?
how do I proceed further
i tried applying cot(a) - cot(b) = sin(b-a)/sin(a).sin(b)
but it is not really taking me anywhere
i also tried equating (2) and (3)
but don't know where to proceed to from there too
$\frac{60 (\sqrt{3}+ 1)}{3 - 1} = 30(\sqrt{3} + 1)$
south's secret twin brother
does that match with the answer?
no worries!
anyone?
please
$-\frac{1}{2} \frac{1}{n + 1}$ is remaining in the second bracket
south's secret twin brother
so -1 in -1/(n + 1) got split into -1/2 and -1/2
they are splitting the denominator right?
the 3 linear factors into respective partial fractions?
@viscid thistle yes the denominator
yes how did 1/2 and and the other 1/2 got there
did he repeated partial fractions again?
no
bro
like
he assumed
that the fraction
with
n denominator
as
A
like the numberator
of that as A
ukw
lemme give a video linl
This precalculus video tutorial provides a basic introduction into partial fraction decomposition. The full version of this video contains plenty of examples and practice problems with repeated linear factors and repeated quadratic factors. Partial fraction decomposition is the process of taking a complex fraction and breaking it into multiple...
i know how to use partial fractions and this doesn't explain how the first ended up as another fraction in the 2nd
i found this on another video but it doesn't explain how from the 1st picture got to the 2nd picture
umm bro
like
what they are doing is
they are taking 1/2(k+2)
as
1/(k+2)
-1/2(k+2)\
x-(x/2) =
+x/2
after then
they just took
2 common
from 1/2k
and
-1/2(k+2)
and -1 common from
1/(k+1) and 1/(k+2)
@arctic meteor
ok i figured it
nice
I am in 9th grade taking foundations in maths -_- Who can teach me precalculus so I can skip my classes.
lol
precalculus
involves what concepts?
also which country are u from
cuz
sylabbus varies
America
damn
so im guessing
ukw
since u understand
english
i presume
why dont you try out yt videos
the organic tutor
organinc chemistry tutor
i find him ver yhelpful
he has a series
for pre calc'
Ok I want to learn harder maths because I hate my classmates in this class.
damn
harder math?
sure
same here bro
so
like
what do you expect
from pre calc
im guesisng
basic interpretations of function
s
and stuff like those
basic algebra
log functions
and stuff?
Is precalc hard?
IDK LMAO
cuz
for me they dont take pre calc and all
they only have calculus
directly
Integral Calculus
they didnt teach me yet
Ok is calc hard?
i taught myself
uhh depends
not actually
its basically algebra
but on steroids
u need to know the identities and stuff
and high pattern recognition
If I don’t even know algebra 1 is it hard? How long it will take to learn all of this?
bro
dont worry about time
the thing is
u have to allow ur mind to think and stuff
like
explore
and grasp
appreciate
the methods
and comprehend the beauty
like
caluclus
feels
like
literally cheating
the universe
Oh ok
calculus
is basically
calculating slope and area under the function
respectively
differential and integral
Sorry I didn’t understand?
Yep
yeah
so its basically
how y changes wrt x
does y change very fast
or does y decrease
or does it remain constant
if the slope is 2
that means
for every unit change in x
y changes by 2
or
y changes by one unit
for every 2 unit chasnge
in x
Ok
to get a better grasp
like
derivate of a function
is basically
calculating this slope
but for quadratic equation and stuff
the slope isnt constant
so it is denoted by
d(f(x)/dx
basically
for very small
infinitisemal changes in x
how y changes
Umm I didn’t get can you simplify?
umm
this might look very complex
but try to understand first
what individual terms in the graph mean
once ur done tell me
Y means front and X means under
Oh ok
yeah can u understand?
the individual terms?
ignore alpha and beta
those denote angles
but we dont need them now
so basically
when i take
the interval of x
for some value
i dont get the actual
slope
lemme show you
Not at all
Depends from person to person. But putting enough effort in, and making sure there's no holes in your knowledge, no, precalc isn't too hard
https://youtu.be/4EMbtrRj0Vk?si=9BMd7pWlvhKg78kc
https://youtu.be/2wrPGtP61fo?si=_-2fA4Wj8--XNhqZ
https://youtube.com/playlist?list=PLE88E3C9C7791BD2D&si=VyAwqIvUKjcuxpee
Watch these in order then you'll be good to go
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Anybody studied the whole precalc on Khan Academy? Do you think Khan covers everything?
You can cross reference with the topic list in AP precalc if you feel like it missing something. GL if u gonna do it
Is it not just [-7,4] [8,infinity)?
Have u already tried that
If it's not then [8,9] or [8,9), no?
it did not work
What did it say the solution was
mb im on the next one
Alr
Try x<=-3 3<=x>=0 x>=7
it said this
Hm
Can you try and use the actual symbol for => and <= instead of the rough one
The one with the line through it
can someone please explain how we can say if the inverse of a function exists
like what exactly is "bijective" and how can we know by just seeing its domain and range
In short for every value in range theres exactly one value of x in the domain
That is mapped to it
We dont know that by just the domain and range
We judged it by seeing the graph and stuff
,w graph cosx
See so in here for 0 to pi
See so in here for 0 to pi
You get two values of x for any values of sin(x)
Except 1
For -pi/2 to pi/2 theres a unique value
yeah i got that
There are two xs
yes
For cos its principal domain is 0 to pi yea
But you can really just input any value from -inf to inf
Like every value of cosx that can ever be reached by subbing any value of x can be reached by subbing [0,pi]
Idk the rigorous definition
But this is the essence
okay
so
the summary is
if a function has only one value at a point
its inverse exists?
oh
because
Uh can you word it better
Kinda confusing
if a function is bijective
Ye
and the reason is that
if there's two values, you'd be confused
where to go back to?
Yeps
More like both will be an answer
But by the definition of function for f(x) to be a function for every x there can be at most one value of f(x)
do we learn the graph of each trigonometric function? because the place i am learning from is just like since we can see the domain of the function is this and this, we can say its inverse exists
but then why is it not that for sin(x)
It will be better if you learn it yea
okay
It is
bro
So they changed the domain
To [-pi/2,pi/2]
What is?
.
Nope
Its just the definition of a function
,w define function
,w define a function
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,w function
....
okay so
Just google it lmao wolfram is dumb
this may sound dumb but
my question is
when we were not studying itf
like, only trigonometric functions
we did not change the domain, right?
Ye
then does that not defy the definition of a function?
Nope? For every value of x theres only one value of that function
So like sin(pi/2) is 1 there are not multiple values that satisfy it
Google the definition of function btw it feels like i didnt explain properly i may have missed some shit
Ask away