#math-help
1 messages · Page 38 of 1
Leave a space between the command and the formula
Can anyone do ittt
Don't think so, you have to go through sigma
it was in a math competition and i couldnt do it 😦
i lost gold 😭
and now i can still not solve it
Ooh that might hurt :(
i tried to brute force it but ran out of time
it follows the general formula of n^2 - 1 starting n = 2
to n = 49
Help plsss (this is ARTITHMETIC SERIES)
oh
can you do 1 by yourself ye?
Ok, fyi, the formula for arithmetic series is ((the last term+the first term)* the no. terms)/2
okayyy
the no. terms can be determined by (the last term - the first term)*the difference between each term + 1
(you multiply first then +1)
now you might be able to figure it out :)?
so multiply the first term then add 1?
the difference between the first and last term * the differerence between any 2 terms, then + 1
for example, for a, the first term is -6, the number of terms is 20, and the total is -690
using this, you can figure out the last term right?
the formula basically means the total
total of the series
which is S
Ok, good luck, I gotta go
okioki thank you so much
have you solved it yet?
Not yet
Holy crap thanks for the super detailed answer! I got to the same answer but I don’t think I fully understood what I did. 👍🏻
lol, no worries
this is not a , this is 1
ohhhh
they asked us to consider numbers between 2 to 43, so he numbers from 2 to 43 is the range
ohh okay
2 d isnt clear, Is it to find the sum of the series upto the 1000th term or till the series reaches 1000?
it just says evaluate the series to the given term
wait can you check if my answer is right
it is to find the sum I think
thats what i got too
yea i think so
substitute in the formula and solve
@wicked perch Its written 1000th . If they mean to find the sum till the 1000th term of the series, this is how you do it
Get it cleared by asking some of your friends or your teacher
yes okayokay
thank you so much for the help
i really didn't know how to start this really helped so much
thankyou!!!
You can always start by writing down what is given to you and then writing down what to find. See if there are any formulas which connects the both and start from there
yes it's like applying physics formula for motion
yeaa i knew what the formulas were i was just having trouble with the steps and stuff
good luck Alex
Anyone know what's the answer to this? Been thinking for a bit but i don't have any good explanations/answers T_T
can anyone explain why this cancels out?
Both 46 and 4 is divisible by 2, there fore you can divide both numbers by two
Just like how 2/4 = 1/2
helloo help me with this geometric sequence problem pls 🥲
does anyone know why it became -sin?
You can mathematically get it using the sin(a+b) formula I guess
But the most intuitive way of seeing it is that, if you add 3pi to your angle, you make an entire turn and a half around the trigonometric circle. Therefore, 3pi+2x^5 and 2x^5 are completely opposite on the circle. That means that, when the sine of one increase, the sine of the other HAS to decrease. => opposite reactions => justifies the - sign
Do you know what I mean ?
Ok let me illustrate it
I will wait, thank you
dm
ok
can someone help me with c?
I'd say +inf, because if you follow basic paths like (x,y,z) = (s,0,0) or (0,s,0) you always get lim s->0 f(s) = +inf
Oh no nevermind
It's both + and - inf because the path (-s,0,0) leads to f(s) = -1/3s, which tends to -inf when positive s tends to 0
pls
-ysin(xy) / 1+xsin(xy)
at the end i wrote sin(xy) times x instead of xsin
Ok thanks that makes sense
Can someone help me with this question?
can anyone help me to transform this into piecewise function?
PR=13, QR=12, PQ=5 so sinP= 12/13, cosP=5/13, tan P=12/5
somebody pls elp!
use pythagorean to determine pq and qr then just soh cah toa and find the ratios
okaay ty
Hi, can anyone help me understand how the expansion of sigma was done here?
first, we'll give r=1 and write the equation. Then will give r=2 , rewrite the equation with r values 2, this is repeated until you give values from 1 to 10 and then sum all 10 terms
-1 powered to an odd number is -1 and powered to an even number is +1, That's why all the odd terms are negative and even terms positive
Hi ... I need a study partner for statistics 🙋🏻♀️
I got A but the books answer is D, who’s right?
It’s a 30-60-90 triangle when you draw a line down point A to the x-axis
Ok so slope = rise over run
rise/run = sqrt 3
which means if we drop a perpendicular from A to the x axis, the perpendicular is larger leg
so it should be 60 degrees
since oab is opposite to that perpendicular
@hardy falcon
plz correct me if im wrong
Let's name the distance between each circle d (because it is = the diameter of all circles, but it doesn't matter that much actually) and the vertical distance between each center h
Using the formula of the area of a triangle (B * H / 2), we get that dh/2 = 3.14 for the green triangle
The key to solving this exercise is realising that the red triangle has exactly the same height H (= h) and a base B twice as long as the green triangle base (= 2d)
Therefore, its area, according to the formula = (2d)h/2 = 2(dh/2) = 2*3.14 (accordingly to what we found earlier)
Therefore the area of the red triangle is 6.28
The graph is not drawn to scale. You can clearly see it because the slope sqrt(3) ~= 1.7 is higher than 1, however on the graph it seems to be less than 1 (because under the 45° line)
@cyan night is right. Although my way of solving it would've been :
Since f(x) = sqrt(3) x and A arbitrarily lies on the graph of f(x), let's just conveniently say that A = (1,sqrt(3))
(now we have formed a right triangle with the points (0,0), (1,0) and A)
Now, let's find our angle a
Since tan(a) = sqrt(3)/1 = sqrt(3), that means a = arctan(sqrt(3)) = pi/3
Quick tip : from now on, don't try to solve graphically. You're above that level, and you'll start seeing more and more poorly drawn graphs, with a scale that doesn't match the actual info given in the question
Do you think the answer is A or D?
I answered
yall answered in degrees they want the answer in radians
Thank you 😭😭😭
The book also taught me that
then u should know that 60º is pi/3
Lemme check (degrees to radians is fairly new to me, I learned it this morning)
pi radian = 180º
Yea I got pi/3 😄
so to convert degrees into radians you have to divide by 180 and to convert from radians to degrees you have to multiply by 180
yep
@steep swan @hardy falcon Well I answered in radians, knowing that the possible answers were also expressed in radians ?
ah apologies i didnt see the radians answer among the wall of text x
np ^^
I dum 🥲
where did they pull 3 from?
Substract 6 to both sides, then substract sqrt(s) from both sides
There you go
Hi, thank you so much for explaining this. But, I'm still a bit confused about how we are giving negative power to the expression. Can you please help me understand that?
we are not giving negative power
the number is -1
-1 powered to 2 is -1 * -1 which is +1
-1 powered to an even number would similarly give a positive 1
Because two negatives , when multiplied , would give positive
(-1)^3 = -1 * -1 * -1 = -1
similarly when powered with an odd number answer will be -1 and when powered with an even number , it will be +1
did you get it?
i am not exactly getting how sigma is working here & what is the significance of (-1)^r here
that's given in the equation right?
we just go by the given equation
Alright, thank you so much!
ayayay okii thankyou soo much
a•a = 1 for all a in {i,j,k}
a•b = 0 for all a,b in {i,j,k} such that a != b (is not equal)
Develop with a basic distribution
i just reflected the graph over x by -f(x) but some dude raised a question about it being over the origin so it has to be both over x-axis and y-axis
not too sure on what the question means by over the origin ngl
try relating it to 1/1x2 + 1/2x3 +...+ 1/4041x4042 = 2-1/1x2 + 3-2/2x3 +... + 4042-4041/4041x4042 = 1 - 1/2+1/2-1/3+1/3-1/4...-1/4041+1/4041-1/4042 = 1-1/4042
idk how to latex sorry
you can take a factor of 2x out
that inside sum is a well known result, which you can derive by hand by taking partial fractions
I would highly encourage you to actually go through and derive that, it's a really good exercise in pattern recognition
But from there, you can just substitute in n = 4041, and solve for x!
Yeah
There's a whole channel dedicated to that if you want
yeah the channel that latex dms me whenever i run the ,help command
=help
Ok, thanks
can someone pls help me on B
f'(a) is the slope of the tangent line of f at point x=a
Since you are given two points that belong to the line tangent to f at x=40, all you need to do is calculate the slope of that straight line to find f'(40)
@tough elk
pls help ;-;
do i just reflect in the xaxis or yaxis and leave it there or is there something im missing
Quick questions guys, can a square root be in the denominator?
yes but it better not be -1 in that square root
are the first and last choices correct?
i think the last one is the correct answer
My calc Ab and BC teachers told me a function is continuous if you draw the line on the graph without picking up the pen so I'm gonna agree with @shut skiff and say the last one is correct. Also, endpoints have to be defined
im a little lost can someone help me? 
thank you!
🙂
i think it is (4,6)
f is not continuous in x=2, x=4 and x=6
and the only answer that has not those numbers are (4,6)
actually, (2,4) is right too
anyone know how to differentiate "f(xf(x^2))"
How to solve B
Chain rule
I have no access to paper and it'll be a mess if I write the development here, but I'll try to do that later
@lofty oasis ⬆️
AH knew it, i got confused with the x^2, thank you!
can anyone help me please
does anyone know how to tell if this particular function is continuous (#3)
Okay. I am taking Stats but I want to be able to understand Bayes Rule.
We know for certain that f(x) is continuous everywhere except for x = 0 (since x^2 + 1 and -x are both continuous everywhere), because of this we just need to test the point x = 0 on both x^2 + 1 and -x , which shows that the function is not continuous at x = 0
This way of doing it is essentially a lazy man's way of taking values from both the left and the right, since we know that x^2 + 1 and -x are both well defined at x = 0
3b1b has a great video on Bayes rule
Perhaps the most important formula in probability.
Help fund future projects: https://www.patreon.com/3blue1brown
An equally valuable form of support is to simply share some of the videos.
Special thanks to these supporters: http://3b1b.co/bayes-thanks
Home page: https://www.3blue1brown.com
The quick proof: https://youtu.be/U_85TaXbeIo
Intera...
thank you!
i have problems finding the difference between contradiction and contraposition proofs
i watch videos and i keep feel like they are similar
habibi
I thought it was like calculation stuff
I don't know, sorry to disappoint you
What is this from?
mhm wait
Ok
Ig its from mathematical logic
can you elaborate?
Ok
why
Can you help me please🙏
A batch of 30 products contains 10% of the defect. Find the probability that among the 7 products taken by chance: a) only 2 defective; b) no defective.
I mean don't say Thankyou haha
anyone know how?
It's because you're getting head at the xth flip so you'd get (x-1) tails before that
Both head and tail have a probability of 1/2
So you'd multiply (1/2) x-1 times
And then the probability of getting a head
Heeeyyy
Despite your confusion, contraposition and contradiction are indeed different
Contraposition means that proving that P => Q (if P then Q) is equivalent to proving that ~Q => ~P (if Not Q then Not P)
Quick example :
If you're carrying a banana in your hand (P), that means you're carrying a fruit (Q)
On the contrary, if you're NOT carrying any fruit in your hand (~Q), that means you CANNOT be carrying a banana (~P)
a quick dumb question from someone not so well equipped in maths: when calculating percentages why does x*0.90=90% of x and x÷1.10=/= 90% of x
:))
But don't get mislead ; carrying a fruit (Q) does not necessarily mean you're carrying a banana (P)
Showing P => Q is equivalent to showing that ~Q => ~P, but it has NOTHING to see with Q => P (the dependency relation of P and Q is one-sided)
Proving by contradiction means that, instead of starting a proof with P to show a theorem holds, you'll start with ~P (Not P) to show that, with such initial conditions (hypothesis), you can't get to a conclusion without having to contradict your hypothesis (~P) or run into a critical error. Therefore, your initial condition HAS TO BE P for the theorem (or whatever you're trying to prove) to hold
Quick example :
Let's prove that all integers have to be "either even or odd" (P)
Method 1) You could take all the integers one at a time, and verify that they are indeed even OR odd (P)
Technically, it would work, but would require an infinite amount of time and energy to get to the end of the proof (I'm sure you know there are many ... many existing integers)
Method 2) Or you could use contradiction. Take any integer that is both even and odd (~P) and let's call it c (we just imagine c exists, but we have no idea about its value). Now, our goal is to try to prove that c exists and to get its value.
Since c is even, we could write c = 2n (where n is an integer).
But since c is also odd, we could write c = 2m+1 (where m is another integer).
Therefore, using c = 2n and c = 2m+1, we can get to 2n = 2m <=> 2(n-m). n and m being integers, that means (n-m) is also an integer, and thus 2(n-m) is an even integer. But 1 is odd. That would mean that, if c was both odd and even at the same time (no matter its precise value), we'd get to an impossible situation where an even number (2n-2m) would be equal to an odd number (1). Thefore, c CANNOT be "odd and even" (Starting with any integer c that respects ~P always leads to an error, that means all integers must respect P)
TakeRep <User:User> [Num:Whole number]
Invalid arguments provided: Too many users with the name: (Amoxicillin_, potatomato, -Dr Chlorine, -red, -🔰Lofi Boy®, - Ave Maria, - Deadfall) Please re-run the command with a narrower search, mention or ID.
Conclusion
Contraposition : you use the depedency of two theorems (P and Q) to switch your proof from P => Q to ~Q => ~P
Contradiction : to show that P => Q is true, you show that ~P => ... inevitably leads to some error (or contradiction with ~P)
TakeRep <User:User> [Num:Whole number]
Invalid arguments provided: User "-\nConclusion\nContraposition" not found
Hope it helps @cyan night
anyone have any good sources for learning eigen vectors / values with the use of matrices ??
Because 1/1.1 = 10/11 != 0.9 = 9/10
For visualisation of the concept : 3brown1blue's yt video will do
For the technical stuff and a deeper approach : G. STRANG's lectures in MIT (1806 Linear Algebra) are perfect to me
cheers 🤙🏻
haha makes sense when u say it like that ty
I will watch it. Thanks
5th line is wrong. It should be :
y(x-1) = 3x-2
-3x shifts from the left side to the right side, but the -2 stays on the right side : it shouldn't have been turned into +2
Nope, this is wrongly drawn. You could ease the task by sketching the y = x graph so that it acts as a mirror
J bro
yesss tysm for the effort! i tried correlating the examples ive seen of contraposition and contradiction and it does really make sense. briefly, does it mean that contraposition shows that when the result doesnt apply (~Q) then you cannot obtain P, and contradiction shows that when the hypothesis doesnt apply (~P) then you cannot obtain Q?
Hey could anybody help me with 16 and 17 please? Much appreciated!
Find the area of the surfaces of the shapes made up of rectangular parallelepipeds.
Pls help
divide it into many rectangles
especially the top
divide the top into 3 rectangles
find area of each then add
You can use contradiction, but it's not the simplest way to do it
For questions like these, you're basically going to want to find where equality is
And then test either side
it isnt a =< actually
i just used algebra to do it
anyone know how ? i need help for the probablity test 😦
damn
Yeah it pretty much sums it up. For contraposition : you show that the absence of consequence is due to the absence of cause
- cos(x) = sqrt[1 - sin²(x)] = sqrt[1 - (8/17)²]
From there :
sin(2x) = 2 sin(x) cos(x)
cos(2x) = cos²(x) - sin²(x)
tan(2x) = sin(2x)/cos(2x)
- looks good to me, but maybe your teacher was expecting 1-sin²(x) instead of (1-sinx)(1+sinx), even though they are the same
Or you could also replace cos(x) by sin(90°-x)
For the First equation : px(x) gives you the odds that the first heads appears on the xth flip. Now Pr(X=1,3,5,...) = Pr(X=1) + Pr(X=3) + Pr(X=5) + .... = (1/2) + (1/2)^3 + (1/2)^5 + .... So you are summing up all (1/2)^k for every odd number k. A different way to do this is to sum up all (1/2)^(2x-1) for every natural number x, because 2x-1 will always be an odd number. That is how you get to that first infinite summation of Px(2x-1)
thank you my friend
how do u solve this?
kind of confused on what to do next after reading the question
Answer lol
Nah seriously, transpose both sides, you'll get a 3x3 linear system Ax = b, where A is the big 3x3 matrix in the question, x = (p, q, r) and b = (3, 0, 1)
To solve the system, try and see if the determinant of A is different from 0. If it is, pre-multiply both sides by the inverse of A, so you'll get something like x = A^(-1) b, since A^(-1) A = I, which is the identity matrix
Once you have solved the system for p,q and r, just use the values you got for them to compute the little 2p + q - r at the end
Note : x and p are 3x1 vectors (thus vertical)
Note 2 : The reason A and x switch places when transposed is because transposition works such that (AB)t = Bt At
help lol
X+20/y+20 = 5/7
X-5/y-5 = 5/6
Use these two equations fo solve it
Lmk if you need me to explain the equations
Hi, so we had to answer true or false and give an explanation
is there anything wrong with what i've written
any answers are appreciated
@ember kernel Thank you!
Could anyone please explain the first couple lines of this example? I have never seen this trig identity before.
Looks good
I believe it's the harmonic form of trig functions, here in the first few lines, it seems to be deriving it, the first line is expanding sin by using compound angle formula, the second line is making comparisons
R is same as your A
ah got it, did this and solved it, did think of going for this approach thx alot
Does someone know how to simplify this even further?
Thanks :))
Hi can someone help me out? I need to find all the coordinates between (0, pi) where the tangent t to the graph of the function parallel is with L
This is what I had but it’s not correct what did I do wrong/ forgot
uhm ... I ... I can't understand what it means
Danish
Yeah but ... well ... I still can't work and help you if you don't give me proper material to work with, like a translated screenshot
Explanations look good but the only thing I would adjust is your reasoning for the first part. “An empty set does not contain anything”. I would change “anything” to “any element” here since the empty set does indeed contain the empty set (but as a set).
Thanks I'll keep it it mind :))
Hi can someone help me with Q8b? I just need help with finding the value of A. The A value I found doesn’t match the book’s answer. Any help is very much appreciated!! [PS: pls do ping me thks :)]
im sorry i suck at math ._.
A few tips for a solid start :
- The sizes of the whitesquares don't matter, since we're only interested in the intersection areas.
- For each overlapping white/cyan area, trace a line that goes from the center of the cyan square to its corner, to split each area in two. That way, you'll transform 3 undefined shapes into 6 triangles. You know the formula for the area of a triangle
thankyou thankyou but what should i take as bases of triangle hights will be the same as theyre from centre
bases will vary right?
Yup, but you know that the angle a the corner of a square is 90°
how to factor:
z^4 + 64
(I also found another, very easy way, of solving this exercise, but it's not really "good" as it exploits the amount of info contained in the question)
So not very rigorous
whats the point of spliting all triangles into 2,ig two of them are already right angled
aight show me
On the drawing yes, but they could be rotated in all kinds of way
wait if we rotate white squares
it will be 1/4
is this allowed?
But it relies on the fact that the question gives you no precise rotations info for the triangle, so you just """guess""" the cyan area must be the same no matter how the white squares are placed
But """guessing""" isn't the math way of solving it
ye agreed
aight i grant you 2hrs do what you can comrade!
thankyou tho
Ummh
Have you learnt about cosine rule ?
a² = b² + c² - 2bc cos(alpha)
@coarse cypress
can someone help mee ? :((
can anyone help me with this question?
Can anyone help me with bisecton method i just want to know what im doing is right or not. I dont need answers .
Please ping me if anyone is ready to me help me . Again im saying i want to make sure im doing in the right way only . We can discuss n close within 5 minutes i guess
so please. . .
it should be B
Can anybody tell me the approach?
try setting the speeds under x
let p's speed be x
p = 2r
q = 1.5r
Yea I hab tried but my answer doesn't match with my options😭
A = 4.3 , b = 1/2
tell me if it is correct
Thankyou soo much no one came forward to help ! You guys are amazing ! Keep going god will bless you as always.
can you ask again , i just joined
can someone explain how do i look at this?? 40 1/2 was given in the question
it's just a notation
read as "Forty and a half"
I suggest you read the stuff i send about this topic. Its called pulley constraints. Give it a try after reading
Not today .
hello can someone explain why d/dx was squared to find d2/dx2?
thank you!!
It's just finding the derivative twice, using regular chain rule :)
Thanks!
I just realized now that i have to use quotient rule 😂
I need help again. Is du/dy = (excos(r))/y correct for this problem? Because after inputting the respective values of x, y, z, the answers I'm getting are not in the choices even after rounding them off. Am I missing out on something?
Which of the following point can lie on the line which passes through (12/7,6/7)
and the product of whose intercepts are 6?
which chapter is the easiest?
expect the dotted ones, I've done that already
10, 12 or 13 I'd say
Not sure, as there is only 4 significant figures. Are you sure your calculations are correct? If you are, I suggest asking your teacher about it
Hello, I still can't figure this out, please help me. I don't really need answers from the choices (if there are). I just wanna make sure I'm on the right track. Thank you!
guys need help how can I solve thiss
A circle with diameter 10 centimeters has an arc that is made from a central angle with degree measure 75. Find the arclength in centimeters. The following steps and conclusion form part of the solution: Step 1: Write the formula for arclength, s = rt. Step2: Substitute r = 10 and t = 75 into the formula, s = (10)(75). Step 3: Simply to s = 750. Therefore, the arclength is 750 centimeters. Is the suggested solution correct? Explain.
The formula s = rt is only valid for t (theta) expressed in radians
@brazen spire
So you need to first convert 75° into radians
Hint : ||75° = 5/12 * 180° and 180° = pi [rad]||
Pls help..... Solve this out
there is no point D
if u meant acl then they are equal because angles abc + acl = 90o
and abc + bal = 90o
so bal = acl
yep we were confused over same thing guesss quetion is printed wrong then
HELP
- The angles of a triangle are arranged in ascending order of magnitude. If the difference between two consecutive angles is 10°, find all the three angles.
Q.If two parallel lines are intersected by a transversal, prove that the bisectors of the two pairs of interior angles enclose a rectangle.
I don't know, the answers are only in my teacher, but there is an option about -1/cosa.
yes
Okayy imma send ya my solution
thank you so much
If you don't understand it, I can write clearly
Actually I have to write it is really seems bad
no it is okey i can understand
63/169 99/169 109/169 119/169 129/169
me too :"
Wait I guess I found it
Hey guys could anyone explain this to me please? Thank you so much in advance!
Can anyone here give me a hand with a simple discrete math graph problem?
It says: given a graph G with 10 edges and n vertices, how many sub-graphs of n vertices and 8 edges can be formed from G?
Hi, i'm honestly confused with this question, i think option 4 is incorrect cause generalised eigenvectors are linearly independent so it might be possible to get 2 linearly independent solutions.
The other options are quite confusing and I couldn't find anything helpful from my lecture notes
It would be nice to get an explanation on whether the other options are correct or incorrect ;;
I'm not sure if option 1 is right or not since the equation for generalized eigenvector is (rI-A)^k*u=v
Shall i have to learn Calculus before Coordinate geometry?
I'd say coordinate geometry first
cos^x-sin^x= cos2x. thats the first answer
Oh..okay thanks@ember kernel
hello can someone help me on this please
If I have a continuous non derivable function f(x) and I apply a continuous derivable function g(x) is g(f(x)) derivable?
No. See for yourself :
Thanks!
I was trying to understand why the derivative of a Brownian process Wt does not exist but the derivative of the cube (Wt)^3 does exist
I suppose I will have to ask my uni profesor
Apparently it has something to do with Itos properties
😦
hi, anyone can help me with a combinatoric problem? i dont get the ideo for this one :
How many three-digit numbers are divisible by three by all of their constituent digits?
is a member of S {2, 3, 5, 6, 7, 9} i
thankyou
I have to find a set of parametric equations.
I don´t know how to do this exercise):
Translation:
The line passes through the point (-1,3, -3) and is parallel to v = 5i - j
thanks bro
The sides of the right rectangular pyramid are inclined to the base at an angle of 60 degrees. If the distance from the center of the wall of the foot to the side is 4v3 cm, find the area and volume of the lateral surface.
Anyone?
the parametric equation of the line would be : (-1,3,-3) and x(5,-1), where x is a scalar multiple
help :(
Have you learnt the reduction formula ? That's what Wolfram Alpha starts with for its demonstration
yes
Then, you need to go through it
how do I simplify (−12r to the power of 6) to the power of 2
hello
Can u share the pic it's gonna be easy to understand
216 r^6
@quaint imp
how
Cube of six is 216 and I multiple the power of r (2 ) from 3 =r^6
wait..wdym cube of six is 216...what does that mean @cosmic sequoia
If u multiple 6 three times u will get 216
y by 3
6×6×6 = 216
If someone power is 3 we multiple is 3 Times
OHHHH
Like power of r^2 is 3, than
r^2 × r^2 × r^2 = r^6
so for this example what wud the answer be
or what wud we multiply -12 by
how many times
Here we will multiple both the things twice
2
what things
-12 and t^6
-12 × -12 = 144
t^6 × t^6 = t^12
Final answer = 144 t^12
Ask anything if u have in your mind ?
will do!
Don't worry,cyaa
Multiple 3 Times
U r getting better genius best of luck 👍
Einstein on the way!
let me solve this
@cosmic sequoia
its this right?
46656
@cosmic sequoia
@quaint imp
yyess?
Multiple 3 Times and than put the value
First solve the function
its asking for the answer
Put t= -3 in -8 t^6
Is the answer wrong ?
Check it again it should be -5832
hmm ok
Tell me something
What's the power of -2 in question
It's 3, I multiplied it 3 times I get -8 , same goes for t^2
And than put the value of t as -3 u will get the answer
Yup
Try it ask questions as much as u can, spend time with problems u will get better @quaint imp
got it
i is the root of -1 ryt
عرب؟
someone draw a diagram please:
that the angle between the two tangents drawn from an external point to a circle is supplementary to the angle subtended by the line segment joining the points of contact at the centre.
Admire this skillfully-finger-drawn sketch I did while in the bus
However, I'm not entirely sure it is correct. Please sketch it correctly, with proper scales, etc. and check if both angles actually add up to 180°.
I've a question:
shouldn't the question say "...angle subtended by the line 'segments' joining..."
since there are two lines
joining the points of contact
Yeah it should
Because I sketched my guess on Geogebra and it works (see the 180° at the bottom left)
So there must be a mistake in the question
anyone know how it can be like that? (the red one)
First red circle : trigonometric identity
cos(2a) = cos²a - sin²a ===> cos(2*4x) = cos²(4x) - sin²(4x)
Second red circle : fundamental trigonometric identity
sin²a + cos²a = 1 ===> cos²(4x) - 1 = -sin²(4x)
Just sum that to the other -sin²(4x) in the parenthesis to get -2sin²(4x)
can anyone help me with this: A restaurant sells 33 bowls of soup every 3 days. At this rate, about how many bowls of soup can the restaurant sell in 7 days?
Ans is 77
?
answwr has to be 77
11 in 1 day. so 7x11
Ok
sure
😁 👍
sat question
really?
Nop, too easy for SAT
lol thats what i WAS THINKING
who said it was sat
Thats why you need to study a lot😼
yeah.lol
last option
yes d also
(d)
sum1 says A,B,and D
in genera'
ok
thx
IT CAN ONLY BE ONE
IT DOESNT LET U PIK 2
Guys i solved one question , but i dont know i did right or not . Its bisecton method , can anyone please have a look . . 🤒
hi guys
does anyone have recourses to study about ways to solve problems that involve AM- GM inequalities, Cauchy Schwarz inequality or anything about AM-GM inequalities
something like this?
question
Ramp A and Ramp C ig
if u take tangent of both the ans will be same thus the steepness is the same ...i hope i could help...my studies aren't in english so i don't know if i could explain correctly
Ur welcome!
LAST QUESTION
Ans will be A ..cuz the base are the same ...so the 5+3-4=2
yup got it!
A and C
🙂 thanks!
could anyone help me with this pde chain rule problem? I know that the answers are 2s and 2t
The best way to put this is to use the notation where each function has its variables beside
Therefore we have :
so thats where I got to, I dont see how its simplifies to 2s... do I plug in values for t?
thanks btw
I'm saying I dont know how id use the trig identity to get from 2scos^2(t) + 2ssin^2(t) being equal to 2s
omg
yup
I see now
that's it
thanks a lot!
np ^^
In this function form
What does a, h, and k mean
I’m learning rational functions
Ok? What does the variables mean i don’t get it
its just a parameter
that indicates y is expressable under a fractional form
therefore rational
i think thats what its trying to say
can u take a picture of the whole question
It’s not a question I’m looking for but this formula goes into most questions I’ll just show u an example
How do ik what is a h and k
k is the y intercept
i think they're trying to say that the numerator is 1 number and the denominator is a difference
so for example 11x+12/x = 11+12/x where k = 11 and a/x-h is 12/x
this is for limits right
Rationals
You rewrite the expressions to have that form
First one for you, you see how you just rewrite the expression to fit the form? Then use those values to find what you need I assume
Could anyone please @ me with help to these problems would be super appreciated really struggling with calc haha
1st question is just asking you for the derivative of f(x). You can use the rules you've most likely learnt to differentiate x² and x
@lapis lodge f" is the second derivative. So take the derivative of that given rational twice
to get f’(x) use:
quotient rule - (gf’-fg’)/g^2
or
product rule - (fg’)+(gf’)
… then take the derivative of f’(x) to get f’’(x)
they foiled it:
cos(2x) * (1+cos(2x))
they multiplied the outer number w each of the values in the parentheses so
cos(2x) times 1 and cos(2x) times cos(2x)
which will be:
cos(2x) + cos^2(2x)
o you can use the practice another option and it should show u like answers to similar questions plus it gives a walkthrough sometimes too
not too sure how they wanna answer #11 but that second equation they give u is limit definition so prob just input the first one into that format and simplify
for the second one, i think they’re trying to isolate cos x in one side so
for the first box: they put x² with 1/2 or: x²/2
second box would be: 1 - x²/2
As @cobalt mural
It just as easy as a(1+a) = a+a²
why is TO angle bisector and OT perpendicular to PQ
in integers these are positive integers(1,2,.....) and these are negative integers (-1,-2,-3,....) then what do we call 0. where does zero belong in integers?
It belongs to none, it's just zero
But it does belong to the natural set (integers >= 0)
An integer is a number having a positive or negative sign
you might understand it in this way
Who can help to solve this problem?
what class is this?
??
it's mathematics
what grade are you in?
11
i got 7/10, s stands for true and f stands for false, it was corrected by computer, can anyone tell me which 3 i got wrong so i can learn them 😀
2^3^2 = (2^3)^2 is wrong i belive, that one should have been f
should sqr(144) be +− 12?
2^3^2 = 2^(3^2)
-2^4= -16 because no parentheses
yes
(-2)^-3 = -2/8 = -1/4 i believe
or no
or yes
yes
so you got 5,6,7 incorrect
i believe
5.6.7*
- Isolate y in both expressions to get actual functions.
- Perpendicularity depends on their slopes, so differentiate them first
ok thanks alot, but number 8 is correct then? sqr (144) is not +−12 but only +12?
why did i get a thumbs down
yea i was thinknig 7 was correct
can you explain it to me?
Because in the last one sqrt(-16) = sqrt(-1) * 4
But sqrt(-1) gives you a complex number (if you haven't learnt about these, just ignore it and remember you can't get a real number from a negative square root)
yes and double check (-2)^4 = 16
In case you're wondering :
(-16)^(1/4) = sqrt(sqrt(-16))
ty very clear!
so number 5 and number 10 are incorrect, whuch is the last one?
6
a^(b^c) is not (a^b)^c
Convince yourself by plugging values 2,3,4 into both expressions and using a calculator
yea first one says 2^9 and 2nd says 2^6 right?
No (EDIT : WRONG ACTUALLY IT'S YES)
Pemdas rule
Parenthesis first in the order of operations
So (2³)² = 8² = 64
i panicked because I'm in 10th and i can't do this question 
Ah, I get it))
and the one with parenthesis? 2^3^2=2^9=512?
I'm trying, but it doesn't work on step 2 and 3.Maybe, I'm doing something wrong.
huhh so is 2^3^2=(2^3)^2
i understand the one with parenthesis but not the first one
when i do it on calculator i get the same answer but im not sure if im typing it wrong
ohhh now i see
thanks
thanks alot for the help quentin, ill give the test another try
Show me what you got
one of my answers is wrong
its asking for k which in swedish is angle or inclination of the straight line and also where it crosses the y axis when x =0
i feel like my answer is 100% correct on this one though?
Usually m is for the slope, and k for the y-intercept
Have you tried swapping the values ?
3y=4x+2 y=4/3x+2/3 k1=4/3
y=√2x³ x>0 y=√2x^3/2 y'=3/√2√x
y=-√2x³ x<0 y'=-3/√2*√x
k=-1/k1
I don't even know what to do
ahh its for sure not like that in sweden and i got half point so in that case id get 0 points🤔
perhaps computer is wrong on this one?
i suspect they wanted me to answer 2x on k instead of just 2
Can you send your question again pls ?
Don't want to scroll too much
Wtf my answer is nowhere
By the way, there are answers here
Ok that's what I thought, no real answer
I thought I was going crazy
Oh wait
No
I am going crazy
Nah sry I really don't understand
I tried again and again while in the bus
But I just can't, it's Friday and my brain is off
my brain too))
is the ans 4x^2+y=0 ?
Yes
is the doubt clear or should i explain how?
Can you explain please?
diffrentiate the curve and put dy/dx=-3/4(as they gave all tangents to be perpendicular to the line with slope 4/3.. then you will get the locus of points
got it?
Understand about diffrentiate
whats the relation btw slopes if two lines are perpendicular?
product is -1?
But then sqrt(9x/2) = -3/4, which makes absolutely no sense in the real set
how did you reach up there?
Can you pls show me the solutions? if it's not difficult for you, of course. Just I really confused
Dude, thnx a lot))
😉
I need to find the derivative of 1/x^2 using the definition of derivatives
How do I fit the last expression into the definition ?
Like this looks a little clumsy
OK I'm not familiar with math bot idk why the fractions didn't work
But basically just put the delta x into the fraction
@oblique star like this, and then - f(x)/delta x
guys question
c
its c
can u explain how we wud simplify these
add/subtract like terms
all terms with x^2 are like
similarly, all terms with x are like terms
should be c again
ok lemme check first
🙂
yeah I think ur right
it works
is the answer for this c?
no
how
i did
not added
so it wud be -2x times +7
it would be -2x times everything
but we need like terms
u need like terms for addition and subtraction
its d
yea
wtf is this lang bro damn
d
how
language
are you elementary student
its english....but its also math
no
r/woosh
shh
grade 11
its just a simple logical math, product of negative with negative numbers is positive
guys: I Need help on this one Im almost done
a rectangle of area 672 cm2 is inscribed in a circle of radius 25 cm. determine the perimeter of the rectangle, should I do a system? i am stuck
no wait, i had already done it
The area of a right triangle is 240cm2 and the difference between the areas of the squares constructed on the sides is 644cm2.
determine the length of the hypotenuse of the triangle. was this
here
4x + 6 - 2x + 8
= 4x - 2x + 6 + 8 (A)
= (4 - 2) * x + (6 + 8) (B)
= 2 * x + 14 (C)
= 2x + 14
(A) Via the commutative property of addition (a+b = b+a)
(B) By factoring x out and grouping 6 and 8 in a single parenthesis
(C) By developing the inside of the parentheses
Can anyone here explain concave up vs concave down and how we use that to find the sign of second derivatives? If so please ping me!
This is very cheesy. I learned this in Middle school. You group the like terms together(put a circle around one type of like term. A square around the other types of like terms) and you add them or subtract them. So you group all of the x^2's, then the x's, and then the constant values(the one's without an x next to them.
That is the general way to do it.
I hope my explanation was comprehensible.
can some one help me with this
Math explained in easy language, plus puzzles, games, quizzes, worksheets and a forum. For K-12 kids, teachers and parents.
A student argues that-there are 11 possible outcomes 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12. Therefore, each of them has a probability 111. Do you agree with this argument? Justify your answer.
Im just going to assume that you meant 1/11. Since we aren't given any information about the distributions of the outcomes, just a list of final outcomes, we cannot make a determination of the probability of each outcome. Suppose we had a jar which held exactly 1000 2's, and then one of each other number. Then the probability of getting a 2 would be 1000/1010, and the probability of getting {3,4,5,6,7,8,9,10,11,12} = 10/101. Clearly the possible outcomes are the same as above, but the probability of each is not 1/11.
Suppose we had a jar which held exactly 1000 2's, and then one of each other number. Then the probability of getting a 2 would be 1000/1010
I didn't understand this @lofty arch
I would prove it by plugging in p into the function and seeing if you get q as the output
the number of outcomes is still 11 (2,3,4,5,6,7,8,9,10,11,12) but there are a lots of 2s. therefore, the probability of receiving the outcomes are not the same
the number of outcomes still remain, but the quantity of each outcome is dissimilar
explain to me what "a jar having 1000 2's means"
so lets put it in a context that we're picking the numbers out of a jar
the jar has 11 outcomes
but there are 1000 2s and just 1 of each other number
still 11 outcomes, right?
@short rover
yes
yeah thats easy
Practice
What kind of "advanced algebraic manipulations" ?
i dunno like being able to manipulate algebra at a high level
Practice
Go through all the steps at first, even the most basic ones
Like 3x+4x = (3+4)x
= 7x
And the more you do it, the more you'll identify patterns and shortcuts that'll make it possible for you to understand that 4x+3x = 7x at first glance
yeah i want it to become intuitive
Practice
do you have resources
Ok thanks
That's not something you can read from somewhere
Just practice your exercises and get some advanced one online
i feel like the homework at school is too easy for me and i want to become specialized in math
Search for advanced exercises online
Or give yourself a messed up expression and try to simplify it
yeah, also wont i need some algebra laws or equations beforehand to solve hard problems?
i find myself not knowing any at all
other than some simple rules
I'm going afk
Send me just one dm so i remember to answer you in a few minutes
Ok, ill also go dinner now, cya later
How much you have left is not a sum
No. What I mean is : give yourself hard problems that you can solve now. I'm not asking you to demonstrate every existing theorem in the world from scratch. Just find something adapted to your level
Ok, so how would i search google if i want to find them
Wait where did u get the 2 and 1
have 3
It's a different example to highlight how the original picture is a bit silly.
If you have 50$ and spend 50$, you will have 0$ left. The left and right side won't add up then either.
tiktok sketchy
See how they don't need to be the same at all? The video is just made to be confusing on purpose
yes
Can anybody explain how the 2nd line of 4(iii) solution happened? My brain is lagging
ok nevermind I got it lol
Uuu thanksss
Just browse what you literally want
Say you want to train your fraction simplification skills, just type in "advanced exercises fraction simplification"
I mean, you're asking me how to google something there, how should I respond ?
Anyone here good at linear algebra
Ya
@shadow garden @shadow garden
There numerator and denominator both is multiplied by 2cos1/2
can anyone help me with this one? 😦