hardware – Example of complex Fourier series

The complex exponential Fourier series of a signal over an interval 0 t To is (a) Determine the numerical value of To (b) What is the mean value of x (t) over the interval (0, to)? (c) Determine the amplitude of the third harmonic component. (d) Determine the phase of the third harmonic component. (e) Write an expression for the third harmonic term of the Fourier series in terms of cosine.
Anyone can solve it?