ChristianBC wrote:
So ? hitthepin?
I did what @blueemu did, but I somehow got 6 and 1, and added them to get 7. Whoops.
Type a math problem and/or solve a math problem
Sort:
For technical stuff like this (no real problem to solve) you can use this tool:
https://www.wolframalpha.com/input/?i=derivative+of++sin+%5B+cos+(tan+t)+%5D
Last part need be taken also. Can't make it a whole.
What is the sum of the inverse-squares of all the natural numbers?
In other words:
x = 1/1^2 + 1/2^2 + 1/3^2 + 1/4^2 + 1/5^2... what is x?
There is other kind of problem that I can actually solve.
Solve the differential equation d^(1/2)y/dx^(1/2)) = y.
@pg. I know it is not complicated. Chain rule. There is no problem to solve. So use a calculator.
What I meant is that the url is split so the link is incomplete.
Trexler3241 wrote:
There is other kind of problem that I can actually solve.
Solve the differential equation d^(1/2)y/dx^(1/2)) = y.
I find it hard to believe that this is actually hard.
ok i'll do my homework!
This is the difference between exercice and problem solving. The second is challenging.
In general we have w'(t)=f'(g(h(t))) x g'(h(t)) x h'(t) ; as f is a sine, it's derivative is cos. Let's replace step by step. (Here x is for multiplication.)
cos(g(h(t))) x g'(h(t)) x h'(t) ; next, g is a cosine so it's derivative is -sin.
cos(cos(h(t))) x -sin(h(t)) x h'(t) ; h is tan so it's derivative is sec^2
cos(cos(tan(t))) x -sin(tan(t)) x sec^2(t)
@trexler. Can you write it with an equation editor, take a screen shot and join the picture?
I don't know if you mean the square root of a derivative or else.
physics_girl wrote:
On that note, an easier problem:
I want to grow a portfolio at 10%, if I am to invest $500,000 into two accounts, paying 4% and 16% respectively, what portion of the $500k will be invested in each?
Show your work
4% x + 16% (500k - x) = 10% 500k
x = 1/2 500k
So half and half.
4% 250k + 16% 250k = 20% 250k = 10% 500k
blueemu wrote:
What is the sum of the inverse-squares of all the natural numbers?
In other words:
x = 1/1^2 + 1/2^2 + 1/3^2 + 1/4^2 + 1/5^2... what is x?
This one is hard. I would try Fourier series or maybe MacLauren but not now. Thanks to all for these great sharing.
ChristianBC wrote:
blueemu wrote:
What is the sum of the inverse-squares of all the natural numbers?
In other words:
x = 1/1^2 + 1/2^2 + 1/3^2 + 1/4^2 + 1/5^2... what is x?
This one is hard. I would try Fourier series or maybe MacLauren but not now. Thanks to all for these great sharing.
If I mentioned Euler and "the Basel problem", would that jog your memory? I believe it's mentioned in Riemann's seminal paper as well.
ChristianBC wrote:
@trexler. Can you write it with an equation editor, take a screen shot and join the picture?
I don't know if you mean the square root of a derivative or else.
It's the half derivative of y = y.
ChristianBC wrote:
This is new to me. Hère is a nice video .
The presenter seems to forget the minus sign in the du=- dt. So, dt= - du.
He doesn't include the minus sign in the further equation for dt.
At 9:22 he explains that u varies from x to 0. So he changes the sign of du to let u vary from 0 to x. There is no mistake there.
blueemu wrote:
ThreeBlueOneBrown has an amazing video on the Fourier transform.
The one on linear algebra is also very nice!
Please Sign Up to comment.
If you need help, please contact our Help and Support team.
Let n equal the highest possible prime number.
Multiply all of the primes together, from 2 up to n, and add +1 to the final product. Call this number x.
The number x cannot be divisible by any of our primes, because it would leave a remainder of 1.
So our number x must either itself be prime, or much be composed only of prime factors larger than n.
In either case, our assumption of a largest possible prime n is contradicted.