#precalculus
1 messages · Page 90 of 1
Are you sure that's a good idea?
Wdym 👀
Yes I am aware
I'm in my first year
.
Oh that's good then, considering that you mentioned precalc I thought you were a kid
Like me
Lol
Im doing that too, im kinda weak in maths
No more, keep grinding
I studied a lot but i still got a very low score in my quiz 1
Issokay
So I'm gonna study harder 🥲
😭🫂
Thankyou 😭😭🫂🫂
Mine too, it's 1:30am
Fellow indian😭
Sent u req
none
no, i dont wanna tell u. u alr know too much 😭😭😭
Bro i cant even do nun if i know
eh true but still
patrick has elite ball knowedge
HEYYY RICKLI UR AN INFANT
ur the oldest here...
ricklis here
wut
no
mhm
any of you guys know anything about probability
Read mentality to ace math books or summaries
What type of probability
Like geometric for exp?
probability is difficult for me
just use tree diagrams for begginers
combinatorics
theres a probability channel #probability-statistics igs. all ive done is the basics taught in like an "integrated" algebra-stats-geo type course so idrk if im that good
hiiii
hihi
can you prove that at least one of $\pi\pm e$ is irrational
Tangent
Yea it is very simple
Let a = π + e
b = π - e
a + b = (π + e) + (π - e) = 2π
Now, if a and b are both rational, a + b, i.e. 2π should also be rational
But, 2π is not rational (kI = irrational, where k = rational number (other than 0), I = irrational number)
Hence, at least one of a and b is irrational
But we cannot prove that both a and b are irrational
,w is pi +e irrational
can anyone suggest a good youtube channel/playlist/course/series to learn calculus
im familiar with the basics, integrating formula, differentian, UV rule U/V rule etc.
professor leonard and 3b1b
substitution method
oke i'll check them out
thank you
im having trouble with understanding/learning the use of trigonometric formulae in integration, so must i revisit basic trigonometry?
the only problems im having is with the difficult ones
like
int (1/quadratic)
those ones
x^2 - a^2
ohh
otherwise im ok with trigonometry
there's a formula for that
yea
i have written the formulae
hold up
the difficulty im having is with remembering these and implementing during exams
and partial fractions method
like it doesnt seem to occur to me
during examinations
well partial fractions rly doesn't have many formulas
js need to remember the basic cases
i cant seem to remember
like
when i solve questions
i usually kind of have to look at hints
well the only advice i have is to do a ton of problems - important stuff is something you start to retain at that point
what's mtg?
i bought this book second hand as i cannot afford a new one
i mean jee does have pretty good problems (not speaking from experience tho)
so ye
what counts as precalclus?
As per the channel description,
Ohh
Note that us precalculus is a bastardised compilation of stuff under a trenchcoat, at least half of which should have been covered in prerequisite courses
What if I already do calculus but im still precollege?
then go to the #calculus channel.
mhmm
As per whereever you select your roles, the education role is based on the math you do, not the formal education level you're in
Ohh okayy it didnt show up for me before
cuz i pciked i was pre college
I see
ama do so
I think they based it on the "average" American trajectory, where they first do calculus in university
But I digress
mm i agree, i just went into browse channels and handpicked a few early uni like stats, calc that id also want (well im 14 but learning calc outside of school, will take calc when im 15 so i js go there when i need help)
Should I use Desmos for polar or is there another software that’s better
Yeahh i feel u
Desmos is ok
desmos
desmos is good for polar
anyone know how to do this cool stuff
ln is just log base e
what sultan pigeon said. ln and e always cancel each other when written like this: ln(e^x) or e^ln(x) to give x, where can be a function or any other variable
so answers are:
-11
6
sqrt(2)
-3
yeah what the other two said, basically they undo each other sooo its just simplifying basically
Yeah what the other three said, just unwind it like its a tangled noose yk
a) -11
b) 6
c) root(2)
d) -3
is it just to what the power e is to
it is more like a property of log, suppose you had log 10^8, we will assume the base to be 10 for now, you can take the 8 in the front and then you would be left with 8*log10 which is just equal to 8 because log10 with base 10 is 1
Remember ln ^ e or e^ln is always 1
guyss well give me tips this year calculus will start
Yeah, natural log is sort of like a function. Plug in e, get 1
ln(e^a)=aln(e)=1a=a as another example of how this could be useful
make sure you understand algebra, functions,geo, trig, exponentials, logs before starting calc
im also starting calculus this year (well, at the start of the next school year) and, hmm, id say the big thing is to just have strong fundamentals. understand what a trig function looks like before you learn how to differentiate it, and such
also need strong algebra fundamentals for algebraic manipulation purposes
How can we derive log_a^b = b*log_a
its a property
Power Property of Logarithms
Is there a similar one on laws of exponents
define what a log is and raise it to the power
Yes
Is that similar
yeah
Now we know laws of logs are inverses of laws of exponents
Basically imagine you have log((a^m)^n)
And lets say the base of that log is a
we know the result should be m^n
uh
I was trying to relate what’s the addition rules on logs to exponents
oops wait thats what i meant
Then correct
hello
I am working through precalculus by stewart, I was wondering if anybody has advice concerning the amount of exercises I should be doing (there are like 100 per subchapter)
Hey man, if you want to try question related to jee you can try an app marks it have questions you just have to go that app and choose engineering it have specific section mains and advanced
You can do those questions without having to buy MTG books or any book for jee : )
What does MTG stand for?
Modern times group it's just a company which sells book for competitive exam like jee neet bitsat in India( previously i was wrong about the fullform now i have corrected it )
Are you good at Precalculus?
Depends on the level of question
But surely will try my best to solve it
What is Precalculus abt? i've never taken the class b4
uhh
a lot of it is like
algebra review
and then theres like some trig work
log work
Yeah
umm matrices work
learn about some stuff u need for calc like, difference quotient, concavity
just ... what it sounds like. foundations to take calculus and stuff i guess
im in the class rn so there might be stuff im missing in my overview cus like we haven't learned it yet butttt yeah
Oh I did some Precalculus in my Adv Algebra class then
Some previews what we are going to study in calculus and it does act like basic foundation of calc( differentiation and integration)
yeah its like
covering past classes
Doesn't pre mean before?
well like
its like
uh
it just like
goes over some of the stuff u learned in past classes
and builds on it
igs
also something else is like, at my school. you can take precalc in 10th grade if u take integrated 2 in 9th grade
do you learn new ideas?
and pass with an A
What is integrated 2 abt?
inverse of rationals
ummm
WHat is concavity?
its like
the rate of change in the rate of change of a function
like
how to take their inverse
like dyk the inverse of a function rn? like, inverse of x^2 would be sqrt(x). so imagine that with rationals (its just algebraic manipulation that i haven't done before this class(
or if kids in integrated 2 dont pass with an a, they take integrated 3 then precalc in 11th. soooo some kids in my class are learing new stuff from skipping from integrated 2 that was covered in integrated 3
Concavity is like you get to know the curvature of the graph on the basis of Double differentiation ( what sign it's show will tell you how the graph curves is going to be )
yeah, concave down means the graph is changing at a decreasing rate, and concave up means the graph is changing at a increasing rate
If (f(x)) < 0 ( negative ) it's going to downward parabola
If (f(x))>0 ( positive) it's going to be upward parabola
im assuming you mean f''(x) for like second derivative
Yeahh
Bruhh
Nvm
So you are doing Integrated math 2 ? what things are taught in that course
And it is from which country ? ( Meant to say who can take this course )
Im in the us, maybe its a california thing dk abiut other states, here 9th, 10th grade (accelerated versus regular track)
no thats what accelerated 9th graders on the advanced track take
im in ap precalc. , um lemme google the contents (dont go after me for ai overview)
Sure

Thanks for information
hmmm
Can you give me an example please?
What does curvature mean?
In basic sense it means curve ---> ( <--- like this
?
Ohh okay. Thanks
She meant to say curve but more in a professional way
like
concave up means its increasing mire and more
if increasing you can think of this like, an exponential
if decreasing but concave up, that means its decreasing but getting less decreasing, closer to 0
and if its decreasing concave down, it keeps deceeasing by more and more
if its increasign concave diwn, its approaching 0, increasing by less and less
I think you should tell her the meaning of concave then go with the definition
What other Precalculus terms are there?
To infinity?
well, functions can switch concavity
Made me thought of sin and cos graph
yeah sin and cos is an example of like
switching concavity
which can be represented
with interval form
anyway I’m now doing Q1: theta, Q2: pi-theta, Q3: pi+theta, Q4: 2pi-theta
U know what I mean
like this
Do u what is that
Good
I think doing radians is way easier then degrees
my teacher said on the ap exam we're expected to work in radians so uh
yeah
My teacher even taught us the shortcut
nicee
Like 7pi/6
pi/6 is 30
Take 7 and multiply by 30
For me that is easier then multiply by 180/pi
yeah thats what i do
in my head
its kinda just what i figured out after a while
but, i have the unit circle memorized in radians anyway, so not like it matters too much
2 pi radians = 360 degrees is all you need tbh
yeah
Do u know what’s this
basically like
if you have like, 5pi/6
and you want the reference angle
5pi/6 is in quadrant 2
pi-5pi/6=pi/6
use pi/6 and change coords signs
to find values
type stuff
make sense?
yeah
uh reference angle is like
that angle in quadrant 1
like the equivalent of it
some people memorize quadrant 1 and just use reference angle to figure out everything sign
Reference angle to memorize
pi/6 radians= 30 degrees
pi/3 radians =60 degrees
pi / 4 radians= 45 degrees
You notice 3 goes to 6 and 6 goes to 3
And 45 take it’s 4 and place it over pi?
Yeah I notice that
frq 3
? do you need help with..?
oh i alr took ap precalc
idk why i didn’t finish what i was gonna say
i loved frq 3
i lwk hate it
i dont mind the calc ones
1 and 2
but 3 and 4 lwk kindda hell for me
got marked off like 3 points on the last test cus i erm might have misread frq3 and misjudged the period..(in my defense it was sumn in fractions) and that test lwk dropped my grade 8% (before curve)
What’s frq3
uh
we're talking bout
frq3 for ap precalc
specific style of question (aka trig modeling)
I’m in ap precal
are you guys also on trig
Idk what that is
um
Yup
the ap exam will give you frq's (long word problems)
i dont like calc frq
i mean frq2 is usually just algebraic manip or regression work
oh for precalc
xd
Oh free response q3??
my teacher hates me
i mean my teacher makes every test close to the ap exam so we're kinda set up for success enough
😭 mines too dw
My teacher grades so hard
oop
Genuinely praying on my downfall
tests (half unit) are like 60% of our grade
Same
and we only have like 3 tests this semester
so the last one (our second test of the semester) dropped my grade 8 fricking percent before a curve
went from 106% to 98%
and i lowkgenuinely didn't even do bad i got like a 85 or sumn
He took of the entire question cus I put (2x-2)(2x+2) instead of 4(x-1)(x+1)
Kind My fault tho
oop
Damn
106??? What is ur curves
We don’t get any
He thinks curves are for the weak or smth like that
W teacher
so far all our quizzes (out of 18) got curved down cus idk i think my class struggles with trig-
and then this is the tests scores, the last test got curved 2 points and the first one got curved 3 points
U mean out of 17?
That’s a lot of curve
so they all got bumped down to out of 17
so original score like 14/18 becomes 14/17
yeah
oof
105.8% is insane
i mean it helps the grade alot soo
depends how well ur doing atm
if ur good with ur algebra, functions, geo/trig, exponents/logs you should be fine
If not, it's going to be a struggle
For polar coordinates if I can memorize the diff transformations am I chilling for calc bc?
(Ik how they work)
Wow bro! You are on the top of the line ... Keep it up mate!
Btw @undone pumice
If you don't mind , would you be able to share your tests coz I really want to know how trig and calculus is taught, the standard, the level that it is in your country/ school
um I mean maybe, I'm not in calculus this year though. Next year I'll be in calc ab so i can try
can somebody help me with this equation? I’m still learning calculus
y = x^2 - 4x + 3
Yeah what do want help with?
i’m trying to understand how to factor this
Sure but i would be glad even if you could share the trigonometry one
You know middle term factors?
y = x² - 4x + 3 = x² - 3x - x + 3 = x(x - 3) -1(x-3) = (x - 3)(x - 1)
thats not calculus... but...
do you understand methods like, x factoring,, or others?
pre calculus
yeah i figured
so you wanna think of two numbers that multiply to 3 and add to -1
*add to -4
He has a doubt in quadratics
and if they add to a negative number and multiply to a positive number, then they must both be negative
so what two negative numbers add to -4 and multiply to 3?
so I’m assuming the answer would be -1 and -3 correct?
if you’re breaking it down like that
yup
The roots would be 3 and 1
@rigid pond
So exactly what evelyn said, but you can actually be quick at this method if you can prime factor out the number which you get on multiplying the coefficient of x² and the constant part. Once you can factor it out, you will get the combinations which will give you the desired pair
Nope 1, 3
Only if y = 0
yeah i was gonna tel them to now put it into the parentheses
Yeahh x= 1 or (x-1) = 0 same thing right
so plugging in you would get (x-1)(x-3)=0
and for it to be 0, one of the parenteheses has to equal 0
so either x-1=0, x-3=0
now solve for x and those are the answers~
It's not really calculus... More of quadratic equations
More so pre-calculus
No problem..... Keep learning, calculus isn't tough, trigonometry is
hmmm
eventually, I want to get to that step to where I learn trigonometry but let me start here
active now 
xd yeah i noticed it changed color halfway thru yapping last night
hmmmm
Sure, get hold of algebra first
it was more so of a pre-calculus equation in quadratic function
like u said
Yep exactly that
you dont even need to split the middle term
where a=1 you just need to think of factors of c that sum to b
x^2-4x+3, -3 x -1 = 3 and -3-1 = -4 (b)
is this like the level of differentiation / integration?
#calculus exists.
yeah at a basic level
yeah, as u advance in hs u may wander into topics covered typically uni, i recommend going to all the channels and just cherry pickign what u need. Eg: i habe calculus and stats selected but not other uni topics
omg real (well we did sequences last unit is vectors and matrices for us rho rah)
you guys do vectors in precalc right?
oh ok
its our next unit after trig suposedly
like is it ap precalc
so idk how much in depth it goes tho ik its on our syllabus
yeah unit 4
oh
is it matrices or unit vectors like ijk
whats a unit vector?'
is it like the coordinate plane mapping thing
oh wait no nvm
its like the ijk stuff with the " ^ " thingys on top
uhhh idrk
lemme think
heres all of unit 4
oh yeah
there is unit vectors
yeah thats it
... looks like a fun thing im so very much looking foward to learning sigh well... i guess theres your answer then
is this from ap classroom
yeah
heres like the expanded list of the two lessons covering vectors ^
the rest is like matrix work
holy
What the f is that
my work😛 It's sorted in different layers but I put it all together cuz yes
looks to be about 10 thousand practice problems with diff formulas and identities...
it's identities and e-e-e-estabilishing 🤮
guys we have to learn identities next week
10k problems are a lot it's not even 100 problems
and my teacher isn't even gonna be here
ik it was a joke
Hm nice tho
Starting trigonometry soon after finish basic algebra
dang 💀
noice
you should lowk use like a diagram for all the trig identities
so true
time for vectors YAYAYYAYA
I alr did polar so im skipping that
nice
By basic algebra I mean these identities some basic inequality etc
For kinematics do you need calculus??
You can learn without calc pretty sure
Oh ok
dont think so
like ap physics 1?
algebra should be fine... i think
What do you mean by ap?
i mean you can use calculus but idt its needed, idk tho i haven't taken any like physics or calc yet so
Theres two diff types of kinematics in high school, usually algebra or calc
so you don't need to
ap is like a high school course at "college" level
Oh
for kinematics you likely don't need it
although its useful though
you can use it to "cheat"
Do we need calculus in this sh
uhhhhhhhhhhhhhhh
I mean its giving equations with derivatives
Is this calculus by any chance 😭😭 it's in the theory
yep
Never did calculus before
and the other page was differentiation. so....
uh
glgl
i mean
looks like
not terrible
like basic calc level
prolly ab type stuff in hs
Ah. Well... er. It is kinda undeniably calc. Is my answer.
I'm sending pictures of some exercises just tell me that it is hard or not and we require easy to mid level calc or not 😭
I think for physics you'll probably just learn like very basic calc
I think basic derivatives and integrals and just knowing what they really are should be enough
yeah seems simple enough
does say at the top, "basic formulas" so, doesn't seem like it wants to go much in depth
I guess and I hope so
Yes it says basic
They say it's advanced but we have lower the level
oh
looks like..
related ratess?
Idk man because it is at the very last of the chapter
Yeah related rates I'm pretty sure. Not terrible I suppose
I mean it's not the kind of related rates where you have like three formulas and gotta chain rule taking variables as a function of time so...
And they have like multiple exercises with basic to advanced and they said this is advanced question but we have lowered the difficulty
I see
interesting
After units and dimensions and some basic maths
im just in 9th grade so i haven't taken physics yet but
ah
Preparing for a competitive exam
jee?
I was confused where to start from
🙏
What’s the book called?
Ohhh ok
Allen modules
That makes sense then, if its a comp then its usually harder
Yess it is quite hard
You’re doing Olympiad?
Can say but not entirely Olympiad syllabus
its JEE, from what i've heard its kind of like China's Gaokao or South Korea's... idk the name. Very tough and competitive college entrance exam thing? I believe (idrk, im in us so quite diff here)
GAOKAO????
Yes
It's harder than gaokao
damn, have fun😭
idk which one is harder but i supose they're comparable, likely
HUHHH?
If you compare sheer difficulty
Yea that makes alot more sense then
in terms of sheer difficulty, JEE is not the hardest exam in the world lol. There are a lot of olympiads much tougher than that
Gaokao = more people = more competition
It's the hardest competitive exam
Not the hardest exam
hmm mention competitive here then
Rmo and inmo are way harder if you compare it that way
Idk how you guys do this😭 humbled INSTANTLY
Hm but that doesn't mean jee is any easier
You have 3 hours to solve 75 questions
my mom and dad grew up in a country where basically... if you mess up on the single exam there is, you dont get into college. no ec's and such
4 marks each -1 wrong
lol I know , all I am saying is its far from the hardest exam in the world
Y s
Jeez what the heck
But 17 years give these exams so you can expect it to be one of the hardest in that age group except Olympiads
yeahh my mom got into her second choice college that had the department she majored in because she didn't score nearly so high as she wanted. my dad came to america for college tho.
Well I took the hardest one here … the SAT 😱😱 ikr just put me in Caltech atp
xdxd
haven't taken the sat yet
Sat is easy tbh
i feel like i scored higher this time tho
u got this trust
sat is very easy
Yesn
lowkey don't know why i struggled the first time 💀
Fair, I’m currently looking at international graduate schools for when I finish undergrad (ik I’m still in high school but likeeeee) and if they have graduate entrance exam (manly ETH Zurich)
But lowk after polars should I do complex plane or vectors?
mm fair fair. i see...
hmm
maybe complex
What they ask in sat is this : 😂
In yt they said this is a hard question
yt is clickbait
i mean there are harder questions
module 2 end is a bit weird at times (or... maybe its js my mental fatigue at that point... but....)
hardest sat question ever 😨 what is 1 + 1
(a) 2
(b) 2
(c) 2
(d) 2
Lol
Hai
its c
trust
Maths is easy but idk about other subjects
i answered (d) at first
Its none of these
They might be harder
Idk + C
twin why are we working in unary
Heard someone wrote a proof of 300+ pages proving 1+1=2
Cause Why not 😎
it's called set theory
Yep you heard that right
twin ts was a definite integral, no plus c! rah
Damn
i can do it in one line, those people were (geuninely) dumbasses ngl
I guess
1+1 = 11
AGAHAHAHHAHAHAH
$1+1=1+0^+=(1+0)^+=1^+=2$
literally anything
chat is cooked
literally by definition
We ain't adding numbers as a string
What are these + thingies
String theory?
(trying to bring back order)
peano axioms + successor function
STRING THEORY 😰
ts goes in #calculus bruv
What in the 💀
Gng when do we deal with these in UG?
Real
ik lol
Dk?
no unless you study formal set theory
💀😰😰WAHT
Ooo i see
Ig cs doesn't have that
Me when I realize there’s genuinely levels to math
ts is basic set theory btw
And I thought establishing identities w sum to product was hard
😭lvls I'll break and jus become non existent
Twin we on the same page
ok so basically
lol
running from scary set theory
REAL😭😭😭
N is the natural numers
yes twin lets run away tgt
it's {0, 1, 2, 3, 4, ...}
YES LETS GO
it's the smallest infinite ordinal
SINCE WHEN DID NATURAL NUNBERS START HAVING 0 💀
N = omega
bro 0 is in the natural numbers in set theory
Imma cry
you need it for it to work
because
when we do cardinalities
we need |{}| = 0
if 0 didn't exist, this doesn't make sense
This is legit breaking me 💀
like the number of elements in {}
there isn't anything by definition
so there's 0 elements
Isn't cardinalities basically the number of elements in the set
informally, set theorists count like:
"0, 1, 2, 3. There's 4 elements!"
Hmm I seee
Yes
True that
In set theory yes
to get this there's a very easy method
define the equivalence relation ~ on N * N
This
Um is 0?
as (a,b) ~ (c,d) iff a + d = b + c
Are you a maths major? @tulip fern
no im in 7th grade, 13
then we define Z = (N * N) / ~
So Z = I times infinity divided by zeta plus beta for when zeta is to the greatest integer divided by a complex number?
I ain't believing shit
So it’s over for me
Was this sarcasm
yall are we fried, 13 yr olds be knowing set theory
no, Z = (N * N) / ~ for the equivalence relation (a,b) ~ (c,d) <=> a + d = b + c
It's fake
i'm literally 13 💀
If it's true bro is 2nd Terence tao
nowhere close 😭
Crap, yea mb just had to compartmentalize the relationship between sin divided by Fourier transform
Barely passed the age limit to be on discord 😭
terence tao is more orz than me
HOW TF
nope
then Q = ((Z * Z) \ {0}) / ~ for (a,b) ~ (c,d) <=> ad = bc
this is too basic for anything special ngl
Brah I thought since it goes from -a to a i should check out the even and odd function
Guess dint work
icl i dont understand set theory my school doesn't teach ts
Pls enlighten us
i just do recreational math lol
there are 4 terms on the numerator, the first 3 yield a zero, but not the last one
What is that now 💀
You don't need his level of understanding for set theory
Hmmmm
When are you meant to learn set theory
math that's "fun"?
Like what’s the point of it
ususally never
im working on simplifying it rn
to explore the foundations of math
Recreational math ?
Math that is fun
This sounds interesting
Never heard someone do maths for fun
splitting off the 1 on the right integrand and then putting the other side of
😭I've heard
i mean i like learning calc in my free time
Cubic formula handwritten
cus my schools math is lwk easy
so for example, there's a result known as whitehead's problem*
Same dude
Nicee 👍👍👍
yeah... sigh
Are yall from Europe or like the west
it's been proven that whitehead's problem has no proof, under Con(ZFC)
Im Asian 😰💀
Yess
Bro first complete you class 10th
usa
asian
Go study
My school only offers calc BC in unison with AB, so ppl end up taking the AB exam anyway
What
Lowkey
Although I want to learn calc 2 by November
it's surprising because an algebraic problem has no set-theoretical solution
R u going to high technology
idk what's that
idrc about the high eduction
B tech?
It’s a top stem high school
Yesss
i'm just a random 7th grader
Oh ok
In the us
doing random things
Oh yea I forgot ur not in 8th
What’s 1 to the power of 0
1
1
1
He will write a proof now
okay wait so now if i rewrite it as 2 (def integral from 0 to 1) 1/(x^2+2x+1) dx... then thats a perfect square... and the ln doesn't mean shi ri-
Help
by definition, even as a cardinal
Stop asking him
right lol, I just added it cause I felt like it 
Isn’t a cardinal a bird
formally, 1^0 is the set of functions from 0 to 1
What is |A| when a is null
0
0
||ur evil|| i mean, im evaluating the integral now
IK THAT ONE
So basically infinite
because the cartesian product is {}, the only function is the trivial function {} 😛
so 1^0 = 1
i overanalyze everything so uh ...
anyway i can't tell if im being stupid or for any value of k Isubk is 1...
in general |X|^0 = 1 lol
right
because then the sum from 1 to 4 would be 4......
and then the greater intenger function is ANOTHER DISTRA-
sat is waaay too easy for any college qualing ngl
not that i oppose it i lowk like my free enterance into college
is the answer just 4...?
Requires sat score
all the sat does is filter out idiots ig 
it is
In our case it's jee
man...
that whole question was um..
def tested my knowledge ill say

at the edge of what i can solve
Oh wait is set theory discrete?
oh I see
Universal set theory is true?
no not really
there's some super continuous sets
how do you think the reals are defined?
they don't just pop out of nowhere
yeah it was kinda a struggle icl
took me a bit to work thru the left hand right hand separation integral thing
i recently learned some measure theory
apparently the lebesgue integral is much better than the riemann integral
like the dominated convergence theorem
i suppose after that beast of a probelm glares at hte ln im gonna take a clash royale break 😵💫
Hellow, what websites should i use for practice (specifically calculus) that doesnt have me swapping thru pdfs, im currently at IBAAHL level math.
Pauls online math notes.
Thanks king
New to this bihhhhhh
currently struggling with Precal
and im like wtffff
any help would be cool
hmm
What do you need help with?
what is your class ccurrently learning?
seems normal 
its not that bad
ok but like the jump is crazy
oh wait this is easy
nvm]
oh wait this is REALLY EASY
AYAYAYAYAYAIAYAYA

lol yeah its kind of like similar to the other one
if this book tells me that the proof is left as an exercise for me one more time I will die
litteraly, doing the work for them smh🥀
frfr proofs are one of my weak points which makes "prove this already proved proof" questions even more annoying
oh i hate those
and they show up att in the aops books

"The proof of this theorem requires mathematical induction, which is not discussed until later on. You are asked to prove this in problem 73."
w-wow
thats um...
"It's okay! We'll just make you suffer later. Heh!"
complex numbers is done!😛
🥀
Is it the one that has a^2+b^2
$|a+bi|=\sqrt{a^2+b^2}$ for $a,b \in \mathbb{R}$ if that’s what you’re thinking of
Civil Service Pigeon
It’s abbreviated as x^2 + y^2 in my textbook but I’m pretty sure it’s the same thing
$e$
SUBLAVA
$x+yi$ instead of $a+bi$. They just replaced with $x$ with $a$ and $y$ with $b$, so yes it's the same thing. ($x$, $a$ are just placeholders for the real part and $y$, $b$ are placeholders for the imaginary part.)
Civil Service Pigeon
tldr it's all different ways of writing $|z|=\sqrt{(\operatorname{Re}(z))^2+(\operatorname{Im}(z))^2}$.
Civil Service Pigeon
My teacher gave us this story to remember the sum and difference identities …
thats really impressive
lol
Today I had some complex numbers studies and those had a very neat way of explaining trig identities
Algebraically
And geometrically actually
So the way to think about it is, cos (a+b) is the same as increasing the angle a by angle b
Geometrically on a complex plane, that's the same as multiplying two complex numbers
So you get:
- z1 = cos(a) + isin(a)
- z2 = cos(b) +isin(b)
And essentially, you just multiply them as you'd do with any other expression knowing that i² = -1
And you really just end up with a real expression that doesn't involve i, and an imaginary expression
That real side, is just cos(a+b), and the imaginary expression is just sin(a+b) multiplied by i
you prove that e^(ia)e^(ib) = e^(i(a+b)) first tho, dont you?
You don't really need to
Because you can use the trigonometric form
And that suffices since we can interpret it visually/geometrically
Afaik exponential forms are easier for calculations yeah, but they're not obligatory
Also that's just an exponential property, why would u need to prove it?
Or rather, why would u need to prove it on complex numbers
it's not, you need to explicitly prove it
we "use" e^ix because it works
but to prove that identity
you need to use the cosine + sine addition formulas
because that's how we define it
e^ix = cos x + i sin x is the definition
I'm saying that you don't need e^ix at all
Because cosx +isinx suffices
But if u want to prove it using e^ix then sure ig, it's possible, just not necessary afaik
I hope I'm understanding ur statement correctly
hmm
Oh how interesting
but e^ix = cos x + i sin x by definition
i'm just using shorthand bruv
wait did i read it wrong
oops
._."
It's easier for general computation to just take advantage of exponential properties in calculation
So yeah, it is easy to prove. But my point was that you can utilize trig forms to conclude trig identities in an easy way
That doesn't require much knowledge about exponents and complex numbers


