#help-17
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lim x---> 0 sinθ/θ = 1
okay thats why
got it?
yep
see, 0/0s are nice
yes!
is that what lim x--> 0 sinx/x is communicating?
yep
thanks guys
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What's up guys, kinda dumb silly question but I wanna double check, my problem is
7y + 9y² - 7y² - 6y
I have to simplify the problem but I'm kinda confused because the y²
2y^2+2y
Uh what 😭
y(2y+2)
That answer is wrong and you shouldn't be giving out answers in the first place
So is y² like a whole different thing than y
Group like terms. y^2 is different that y, but you can group the y^2 together and do the same for the y's
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how do I get the domain
f(x)=ln(5−3x)
yes
but how do I put it into like a ordered pair
u mean interval?
ye
this one
on a real number line
then read it out
and write out
it out*
bravo
np
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im confused on how to do this can i get some assistance? i need to describe how i got answer idk how to do it though
in order to be continuous, there can't be a break in the function. So, with that logic, you need to find values where 5bx-6a meets -3b - 4ax at x = -2 as well as -3b - 4ax meets 5x-1 at x = - 2. So how do you think we can do this?
set them equal and solve?
i got b= -2a
so a = -11/14
then u sbusititute it back into the equation
so b is 11/7?
One moment
(sorry wife is calling me for something, I'll return shortly. If someone else answers then cool, if not i'll hit ti back)
Hey Im so sorry, emergency with pet
let's wrap this up
okay so you had the right idea but there might've been a miscalculation somewhere
So when we plug in x = -2 into the top equation, we get -6a -10b, middle equation is 8a - 3b, and finally the bottom equation is -11.
Since they all have to equal one another, then we have the following:
-6a - 10b = 8a - 3b = -11. We can turn this into a system of equations.
-6a - 10b = -11
8a - 3b = -11
So now we can solve the system of equations
want to give it a try real quick?
\begin{align*}
-6a -10b &= ,-11 \
8a - 3b &= ,-11
\end{align*}
MellowDramaLlama
@edgy totem Has your question been resolved?
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how do i find the angle the answer says its pi/3 idk how to get that
which angle are you trying to find?
can you draw the angle you're looking for?
perhaps there are some (right angled) triangles that could help you out
yes
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Surely there has to be a more efficient way to solve this problem than using Pascal's triangle right? How am I supposed to determine the coeffcients?
do you know coefficients
I tried searching on googlee
like do you have a computer there
but i cant find a triangle that goes up to row 20
do you have a computer there??
I do have a computer
what type??
Im not sure, its a PC, but I dont think its designed for like math/pascals triangle lol
Like the computer I have is not related to the school work
I thought it was sth like Casio fx-580
yeah
Free math problem solver answers your algebra homework questions with step-by-step explanations.
i kinda dumb at English
I can try that
$C^k_n = (n!) / (k! * (n - k!))$
Is that a symbol on the calculator?
Nguyễn Tuấn Minh
nCr (maybe)
it then says "Ans nCr __"
I would assume I put 20
but then I get 0 when I press enter again which seems wrong
Ok
all i found is trash
Lol no worries
Its fine if U couldnt find the answer
its Just one homework problem of many
$C^k_n = (n!) / (k! * (n - k!))$
Nguyễn Tuấn Minh
Is that a formula I can use?
maybe calculate by hands maybe find
Yes I can try that
so n in your case is 20
btw 2 must be square in the last term
Ohh I forgot u do that with the exponent thanks
i'm just too bored doing the crazy assignments my teacher assign me to
ok
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I need to factor this trinomial, but I'm stuck on how to do it, could someone help me?
Split 5x into 6x - x and then factor
sorry, what do you mean by split 5x into 6x - x?
nothing
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use this
so?
notice with this you can sub stuff in
^ when you "use" a formula you want to figure out way to make it work
we can think about the trace part later, figure out what's inside first
So do i write it like tr(A× A²adj(A²)?
so tr(A× |A|²I)?
and then do i just find the matrix or is there a shorter trick
OHHHH thanks i got it
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Help please
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hey!!!!!! i need help in trignometry question......
Please show the original problem, exactly as it was stated to you, with the entire original context. A picture or screenshot is best. If the original problem is not in English, then post it anyway! The additional context might still be helpful. Do your best to provide a translation.
It's such a hard question that i am not even able to see it 
so saddd
That's a trigonometry que?
Btw take lcm and try the first derivative test
oh i'm sorry i actually had doubt in this question too from maxima and minima
It is
Sadly
still not able to do it...
It's a increasing function atleast for x > 0 if my calc are correct
Absolute value of x = +√(x²)
I guess this'll help
Nvm my calculations arnt correct 
Oh ok
What did u do 
That's some crucial info 
did u find it?
a true
b false cause it supposed to be 5/6
Function is decreasing for x > 0 so minima should be at x = 1
I hope this time my calculations are correct
What is supposed to be 5/6 minima maxima inflection point 
we want the min value of f(x) so we have to make the max denaminator
put -1 instead of x
Ohh ryt 
than you find 1/2 + 1/3
btw sorry if i cant explain what i want cuz im not so good at english
but im tryin
Fck my calculations are again wrong
Some one find ther derivative of the function and tell wheater it's increasing or decreasing or having a local minima or maxima
Yes
@kindred parcel Has your question been resolved?
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This is 1 of the steps in the solution to a question
How did they integrate sqrt(x) - ln(x) into 2x(sqrt(x))/3 - x(ln(x) - 1)?
I got 2(x^3/2)/3 - xln(x) - x
x^{3/2} = (sqrtx)^3
hmm ok... but for their answer I got 4/3 - 4ln(x) and they got something different
So where did I make my mistake
Wait
I see it
Its supposed to be +4 and +1
Ok my bad
Thank you!
❤️
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Hey
I have almost done this problem
I just need some form of confirmation that i did this problem right ✅️
How did you do it?
I asked chat gpt to check my work and see if i did it right but i am sure it made a mistake lol
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).
Huh what is your problem if i use ai in my private life. I don't trust ai and this is why i came here lol
I only make use in certain situations
For matrix computations maybe using something like GNU octave (free analogue of MATLAB) is more reliable
lol
obviously it’s fine to use otherwise but it’s proven to be highly inaccurate at times for math specifically
Yes i know lol
This is why i came here
I solved the question myself and then i ask ai to check it
@hollow plinth Has your question been resolved?
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So first I got 2x^2 + 9x + p
And I got the discriminant of that and set it > 0
b^2 - 4ac > 0
81 - 4(2)(p) > 0
p < 81/8
But I dont really know what to do with that cause its not at y = 1
Why are you considering the numerator?
Im not really sure what im doing, I was just guessing 🙃
Read the text carefully
You need to read more deeply
What exactly has 2 solutions?
y = 1
Thats what I was saying here
Its not that I didnt read I just dk how to do it lol
So ...
So I dont know 💀
What is y also?
intersecting f_p(x) twice?
This doesn't make sense 😬
Ok then I dont know what is y also
So if both 1 and f_p(x) are equal to y, it follows that...
This also doesn't make sense 😅
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Yeah I think it's better
What does that mean
That your brain should recover a little bit, so that you can somehow reset all the wrong stuff you've thought of doing
I often see that after a break the brain is clean for new reasoning
And sometimes it turns out it gives the correct way of solving a problem
Ok sorry if I kept saying the wrong stuff im just trying to learn
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Don't worry, as you said it's something normal, there's also the saying "you learn by your mistakes"
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Calculate BM in terms of a and c if BM = 2MN and AP = AC
No one answered
Just someone saying bisector theorem I see it coming, or sm like that
But no
it's not
The angle bisector splits the base in ratio of its sides
M yep, I don't how to use that here
tho
Can you draw a perpendicular from B upon AC?
mm I think yes
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( a shuttle number is a number that : the first digit is greater than the second. The second digit is less that the third digit. The third digit is greater than the fourty. The fourty digit is less than the fifty digit... )
How many 7-digit numbers formed by the digits 1, 2, 3, 4, 5, 6 and 7 are shuttle numbers? For example, 4253617 is one of these numbers. But 5372146 is not (2 is greater than 1 and 1 is less than 4) and 2163457 is not either (4 is less than 5).
@loud walrus
Is repetition allowed ?
? So it's not allowed
it is not allowed

What have u tried
i am struggling to start actually, idk how can i combine this
Then don't solve this problem solve a smaller case of this problem ie solve for 3 digit numbers and try to make cases
alright, i will try to do that
@distant perch Has your question been resolved?
Any progress
i am thinking yet, give me just a moment please
that is what i found, 1 means the first digit
so the first one means that are 15 combinations if the first digit is 7
adding it all up i found 70 combinations
Could you identify some pattern?
yes, mainly seeing here with 4 digits but i can't prove anything yet, one moment
the most obvious thing of course is that when the first number is 5 or less we start to remove the lower numbers, so when first digit is 5, we remove 1, when first digit is 4 we remove 2 and so on
Hmm so ur using brute force to do it
Ok think like this u have 10 digits right and u select 3 out of the 10 digits and arrange them in such a way that a1 > a2 and a2< a3
You can select 3 digits out of ten in 10C3 ways
Let the digits be abc can i argue that there will be one digit out of those 3 which will be the smallest let's say b that will be your middle term a2 in this case and the rest a and c can be either a1 Or a3 so a and c will have 2 choices to be arranged into and b our smallest digit only has one choice which is to be the middle term
So total arrangements possible will be 10C3 × 2 × 1
So do you get my argument? 
i am trying to
Ok
sorry, i have to go but i'll consider everything that you said to me, thank you and have a great day
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simple question but whats the 3.7 inches mean?
this is a triangular prism
the 3.7in is the height of the triangle from the right side
thank you but then whats that line with the square
thank you
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That's ncert dude
!status
What step are you on?
1. I don't know where to begin.
2. I have begun but got stuck midway.
3. I got an answer but I was told that it's wrong.
4. I got an answer and would like my work checked.
5. I have a question about someone else's work/solution.
6. I have completed the problem and don't need help anymore. Thank you.
7. None of the above
I'll just rapid fire answer all of them dw
Ques 11 or ques 12?
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how does this work
they pulled out 4/5 to get sinx/x
so (4/5) * 1
but there's no x to plug numbers into
Do you not understand how they pulled 4/5 out?
they just did..?
yes sin4x/4x = sinx/x
no
also if you expand out that second bit, you will realise you get back to the first expression
You can’t divide the 4 in the sin expression like that
$\sin(4x) \neq 4 \cdot \sin(x)$
tobi
Sin4x/4x = 1/4 * sin4x/x
im soooo confused
they just pulled out 4/5 and replaced it with 4/4 by multiplying by 1?
$\frac{\sin(4x)}{5x} = \frac{4}{4} \cdot \frac{\sin(4x)}{5x} = \frac{4}{5} \cdot \frac{\sin(4x)}{4x}$
tobi
$\frac{a}{b} \cdot \frac{c}{d} = \frac{c}{d} \cdot \frac{a}{b}$
tobi
tobi
maybe it gets simpler if I do this once
$\frac{\sin(4x)}{5x} = \frac{4}{4} \cdot \frac{\sin(4x)}{5x} = \frac{4 \cdot \sin(4x)}{4 \cdot 5x} = \frac{4 \cdot \sin(4x)}{20x} = \frac{4}{5} \cdot \frac{\sin(4x)}{4x}$
its not 4/4 * 4sinx/5x
tobi
sure
$\frac{4 \cdot \sin(4x)}{20x} = \frac{4 \cdot \sin(4x)}{5 \cdot 4 \cdot x} = \frac{4}{5} \cdot \frac{\sin(4x)}{4 \cdot x}$
tobi
maybe this here is unclear to you
$\frac{a}{b} \cdot \frac{c}{d} = \frac{a \cdot c}{b \cdot d}$
tobi
this is always true when b and d are not zero
okay thats the next question but you agree with me that we didnt change anything right?
you should also know that constants can be pulled outside of the limit
right
$\lim_{x \to 0}} \frac{4}{5} \cdot \frac{\sin(4x)}{4x}$
tobi
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no
then there is no x value to plug into
yea then im lost
okay thats just untrue
i have definitely plugged in the value into equations
only for continues functions
ah
but limit just means what happens with my function as x approaches that value
it can be the same as plugging in the value, but thats only for continues functions
$\lim_{x \to 0} \frac{4}{5} \cdot \frac{\sin(4x)}{4x} = \frac{4}{5} \cdot \lim_{x \to 0} \cdot \frac{\sin(4x)}{4x}$
Yeah in this case you can basically just do what everyone does and say sin4x/4x tends to 1
tobi
Or if you really want you could change variables to something like u = 4x and then you have the limit as u tends to 0 of sin(u)/u (since this is typically the standard result) but that’s not really needed
You can take constants out of limits
yeah this is not so difficult to show using the definition of the limit
and just do 2 * limx--> 0 (1/x^2)
Because a limit of a product is the product of the limits
well this expression does not make sense in the first place but yes
only if both exist
Well yes
okay so we can take constants out but what do we do with our sinx/x
or sin4x/4x whatever
If you really want to think of it like this you could, but again you don’t really need to:
$\lim_{x \to 0} \frac{x}{x} \neq \lim_{x \to 0} \frac{1}{x} \cdot \lim_{x \to 0} x$
tobi
$\lim_{u \to 0} \frac{\sin(u)}{u} = 1$
tobi
are we doing f(0) tho
you usually prove this geometrically, there are some great videos for this limit
sin*0/0 is just undefined
yes thats what I mean with we never really plug in the value
$\lim_{x \to 0} \frac{4}{5} \cdot \frac{\sin(4x)}{4x} = \lim_{x \to 0} \frac{4}{5} \cdot \lim_{x \to 0} \frac{\sin(4x)}{4x} = \frac{4}{5} \cdot \lim_{x \to 0} \frac{\sin(4x)}{4x}$
sinx/x
we just look at the value we get when we approach 0

brah what am i looking at
sin(x) behaves like x for really small values of x
Yeah gimme a sec
so for very small x we can cancel x and x to get 1 (physics trick) but it gives some intuition why the equation is true
graph of sin and x
eugene_krabs_has_cake
^
you need a definition of limits for that tho
okay i get it now
its literally just the identity
I’m not trying to be THAT rigorous, this should do fine
i know why we can just have 4/5 not how squeeze theorem works unfortunately
so i dont understand how trig functions work here
heres another problem
we turn it into an equivalent form
so we have
well first of all
1/(2xcosx^3)
do i just plug in 0
no
1/2x isn’t continuous at 0
you never plug in that value
what do i do with these type of problems then
Not even considering the numerator
so im not done yet
You would need both to be continuous at 0, here the denominator isn’t
right, so more factoring?
$\lim_{x \to 0^-} \frac{1}{2x \cdot \cos(x^3)}$
cos of 0 is just 1
yes
so i do plug in 0
tobi
i mean id get 1/0
thats bad
we dont divide by zero
but thats the correct idea
you can think about it like this
what happens for values very close to 0
but i want to approach 0 from the left so i can plug values in up to 0 that wont give me 1/0
that are always negative
what happens for cos(x^3) when x is almost 0
you already said it, I just want you to think differently about limits
it approaches 1?
yeah
and what happens for small negative values with 1/x, as x goes to 0 from the left
negative infinity
so for very small values you mulitply 1 with negative infinity
which is just negative infinity
you can (again) ignore the factor of 1/2
because this expression is essentially 1/x?
$\lim_{x \to 0^-} \frac{1}{2x \cdot \cos(x^3)} = \frac{1}{2} \cdot \lim_{x \to 0^-} \frac{1}{x \cdot \cos(x^3)}$
tobi
constants can be pulled outside of the limit
oh thats what u meant
so the idea is that as x approaches 0 from the left f(x) approachs neg inf here
pos inf?
yeah
the cosine term here doesnt matter because cos(0) = 1 and cosine is a continues function
I can recommend trying to understand the epsilon delta definition of a limit
yea its a lot
this helped me with intuition
maybe try to proof:
$\lim_{x \to 4} (5x - 7) = 13$
tobi
well as x gets closer and closer to 4 we get closer and closer to 13 as our solution
idk how to do proofs yet
[
\lim_{{x \to c}} f(x) = L
]
means that for every (\epsilon > 0), there exists a (\delta > 0) such that for every (x),
[
0 < |x - c| < \delta \implies |f(x) - L| < \epsilon
]
tobi
thats the definition of "lim"
and this definition shows that you never plug in the value c here
but maybe thats to much information if you have never seen this before
i have seen it before i just dont understand whats it trying to communicate to me and why i should care about it
epsilon is just the y value right
this i get
yes and if your function is not continues you couldnt shrink the red border as much as you want
if the green gets very close
if its close to 1
why is that problematic
if thats the case the limit does not exist
we get very close to c (x axis)
and look at the y axis and look at what value we approach
in this case we cant approach anything because the function is not continues
Formal derivatives, the epsilon-delta definition, and why L'Hôpital's rule works.
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Timestamps
0:0...
hospitals rule 💔 '
the timestamp is good
ok so ill watch the video but i just have some questions
sure
so for problems like these
i never actually plug in 0
i just want to know whats happening around 0
yes and with around 0 you mean very very close to 0
yeah
yes thats correct but thats not what the limit is equal to here
it gets bigger
$\lim_{x \to 0^-} 12 e^{-2/x} = 12 \lim_{x \to 0^-} e^{-2/x} = 12 \exp(\lim_{x \to 0^-} -2/x)$
tobi
-2/x goes to +inf as x goes to 0 from the left
do you know what I did here?
you isolated it because its the value that actually matters?
on the first step I pulled 12 outside of the limit
tobi
the exponential function is continues tho, so we can interchange limit and function
thats what I did in the 2nd step
got it
so it approaches positive infinity
yes nice
so thats my solution?
yeah
so when in doubt plug in values around 0 to see whats happening
in other words, make a table
for not very crazy functions this will work yes
awesome thanks
you could have functions that oscillate infinitely often next to the value that you are looking at
then i would have to plug in values from the unit circle?
ah
or this function
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i need help with a math question
Ask
@sharp laurel Has your question been resolved?
no
which step specifically?
well i need to find the linear regression
alright
using that table but
i am suppose to type this table in the calculator to find the regression but i dont know how
what calculator are you using?
Texas Instruments TI-36X Pro
can you use desmos?
yea sure
so in desmos you can type "table"
and it'll make a table
you can input all your data in that table
and then type y1 ~ mx1 + b
and it'll give you the values for m and b
as well as the correlation coefficient
ok ok
oh wait
i got it
thanks
i found the decimals
now i basically have to round them up
by putting it into an equation first
thanks bro your a big help
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Linear Algebra. Doesnt vector AB mean adding Vectors A and B, why are they subtracting it for vector V.
Also I don't really get the question either
If it says that Vector V is Vector AB, wouldn't they be the same thing
Or am I just dumb
vector AB points from point A to point B. vector v points from the origin to (2,5). they are mathematically equal because they have the same magnitude and direction
you can find vector AB = B - A
@opal violet Has your question been resolved?
Why can't u just do A + B?
Instead of B - A?
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How am i not getting this right? I swear i got it i can’t understand why its wrong
pay attention to which divide bar is larger
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The formula for s(t) but with a instead of t
So far so good
4.9(-a^2 + t^2)/(a-t)
Or
4.9(t^2 -a^2)/(a-t)
4.9(t-a)(t+a)/(a-t)
-4.9(t-a)(t+a)/(t-a)
Cancel (t-a)
-4.9(t+a)
-4.9t - 4.9a = 0
-4.9t = 4.9a
t = -a
??? Is this making sense
sorry I'm on mobile lmao
This is fine so far
Why are you setting it equal to zero
Because I dont know what else to do
I dont know what "the limit of the function as t approaches a" means
I dont know what a is
So I have no idea what they're asking me to find
It represents the value the function approaches as t approaches a
So you can do direct substitution now
Substitute t=a
t approaches a, not a approaches t
Nvm
Does that mean "approaching"
It’s talking about the specific instant where the object reaches the ground
oh 250
0?
Yeah
Yeah
So sqrt51?
,w 250/4.9
Yeah that’s for the velocity
ohhh
so this is the first answer
The then we do -9.8*(sqrt259/4.9) for the velocity
Typo but yeah
thank you
Anything else?
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how would I set up an infinite sum to solve this
(ik its been like 3 minutes but I really gotta go soon 😭 so <@&286206848099549185> )
hope yall dont mind 😶🌫️
what have you tried?
i think its more just I have no clue how to approach it
the procedure they show for how money ccumulates over time its a weird process, one which depends on the previous outcome after a combination of operations
so its like a nested sort of summation
and I just have no clue how to make it something which can easily be calculated out to infinity
(ie a geometric sum)
i don't think it forms a nice geometric series
ye exactly
so idk what to do 💀
could be potential AGP or some combination of something else
agp meaning?
arithmetico-geometric series
gotchu
what wld u think wld be the best course of action then
wait, could it be I could set it up like a growth rate function
like e^kt
I think you should start by calculating some of the amounts given to charity
then observe the pattern and try to generate its general term
gotchu
ill do that then
this always helps in any sequence and series question
LUL
yea cause I just realized the addition can be interpreted as a 1.05 multiplication
and then multiply that by 0.9
for the amount withdrawn
and u get that 0.945 ratio
aight tyyy
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The uv’ + vu’? Idk how to apply it 😦
Ohh
it is the (first function multiplied by the integral of the second function) minus {Integral of[(dervative of first function)*(integral of second function)]}
sounds complicated
in terms of u and v
Wait so u = e^2x? And v 2xe^2x?
it's u ∫v - ∫ (u' ∫v)
wait
they asked the antiderivative of smtg else though, check
they asked the antiderivative of
x * e^2x
Ye
No 😭
V and U?
yes but from this , there are two terms in the product
what are those
X * e^2x and 2xe^2x?
no no bud
see it's like
the question is trying to confuse you i think
the first half of the question is basically useless
omgg do u mean X and e^2x
just to confuse you i think
Yasss boi you get it

now, we must choose u and v right?
OHH
for uv rule in differentiation
Ye
So u=x and v=e^2x?
there is an order
yess but you guessed it
ohh what is the rule for order?
Prob not
I - inverse trig
L- Logarithmic
A - Algebraic
T - Trigonometric
E - Exponential
so which ever comes first, you take THAT as u
you get it?
Ahh I seee
so whihc becomes u?
X
Nice teaching 
Ye
integral of e^2x is?
1/2 e ^2x?
derivative of x is?
YAS
1?
perfect
Nicee
so it becomes ?
Just 1/2e*2x
(1/2 e ^2x )- ∫ (1* 1/2 e ^2x) dx
Yeppp
or simply
(1/2 e ^2x )- ∫ (1/2 e ^2x) dx
∫ (1/2 e ^2x) dx is ?
1/2 ∫ ( e ^2x) dx
YEP
oooo
what's the e option

Just that
:DD
cheers 🍷
Cheers, ty!
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Do i just leave it at "65" or should i go for "65.009" (shown in the calculator) if yes, how?
Are you supposed to go with decimals or not ?
Then you can continue till you get that 9
So i add both 0 to my answer and the 5?
But if i do that, I'll get .009 first than >503
A number greater than 503
Well, ig you can stop at 6.5 tho
65
65 ?
Yeah, i got 65
65*50.3 ?
Ive only read that you write 327 divided by 50.3 in green
Oh
Then if it is 3270 indeed
Thanks for noticing that😭
It's 6.5
Thankss
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m^2-n^2=2023^2 where m,n is a positive integer, how do i find the smallest m
like ik its (m+n)(m-n) but im not sure how to pick factors of 2023^2 such that m is the smallest
by "smallest" do you mean "closest to 0" or "most negative"
Wish it was smallest n 
fixed it >:(
Should be Closest to 0
ty
did you find the prime factorization of 2023?
hello sir
you should factor (m^2-n^2)
so you'll have to solve m + n = A and m - n = B where AB = 2023^2
(m-n)(m+n)
notice that solving this, you get that m = (A + B)/2 and n = (A - B)/2
good so far?
yep
@thin vale AB sighted
so true
💿
WLOG i will say m > n and A > B
so to minimize m, we have that A + B is as small as possible
can you think of when this would be true?

