Its a problem about probability, I have the solution ussing other ways, but i want to check if i´m doing well.There is not a student problem, its a problem from 2019 in Spain to select staff in order to teach maths in high school.
We have a isosceles triangle l, an angle is a random variable X between 0 and pi/2 X=kx(pi-x)
I have to calculate the expected value, and i try to do the integral... other people calculate the density function and made the integral, i thought i can do directly the integral from 0 to pi/2 x A(x)