Today i asked TI-interactive for doing this:
But the answer is exactly the same as I typed!?
After all TI was able to answer this one:
integral(sin(x*2*pi),x) = ............
From this answer I was able to integrate the first one myself and I ended up with:
integral(abs(sin(x*2*pi)),x) = (2*floor(2*x) - cos(pi*mod(2*x,1))) / (2*pi)
Now I discovered that the method that TI uses when it isn't able to integrate is very inexact.
integral(abs(sin(x*2*pi)),x,5,63) = 36.9238551611
Making use of my integration:
integral(abs(sin(x*2*pi)),x,5,63) = 116/pi = 36.9239467973
Now I have two questions:
What is the name of the method which TI uses in a situation like this?
How comes it that TI isn't able to integrate a simple function, which I am able to integrate?