i attached the Q photo.

I'm very confused by this question.

as shown the photo, the signal is shifted to the right by 5ms.

the Q ask for equation Vo(t) at -5ms<t<5ms, can i say that it is a sine wave?

and given that 1 period is 20ms, so the freq is 50hz. so the equation Vo(t)=sin(100'pie't) from -5ms<t<5ms.

next i'm required to find the fourier series of the Vo(t).
I search the internet, they stated that the period will be half of the original sine signal. is this correct? after i do the working, my coefficent of a,n =0 which is wrong.

anyone can enlighten me?

 

For your equation, what is v(t=0s)? Does this match the graph?