Let f(t) be defined by if and if .

1)Calculate , .

Attempt: After a lot of algebra, I reached for all . I don't know how to check it out in Mathematica so I'd like to know if you could verify my answer. For , I get .

2)Calculate . Attempt: Not done yet, but if I remember well I should use Parseval identity. Is that right?

3)Study the pointwise convergence of the Fourier series of f. Attempt: Not done yet, but I think I should look at and see if it's equal to the function f?