# fourier coefficients of a square wave

Discussion in 'Homework Help' started by jstrike21, Feb 3, 2010.

1. ### jstrike21 Thread Starter Member

Sep 24, 2009
104
0
I was given fundamental period Fo=4s so this means Wo=pi/2.
Then , x(t)={1, 0<t<2 and 2, 2<t<4
x(t) is periodic.
I plotted the sine wave now i have to write the formula for the fourier coefficients Ak and compute A0, A1, and A2.

Im not sure how to get a formula for x(t).

2. ### t_n_k AAC Fanatic!

Mar 6, 2009
5,448
790
For the interval of integration t=0 to 2

x(t)= 1

For the interval of integration t=2 to 4

x(t)= 2

3. ### jstrike21 Thread Starter Member

Sep 24, 2009
104
0
wow I'm going to go crawl in a hole and not show my face again

4. ### jstrike21 Thread Starter Member

Sep 24, 2009
104
0
I have Ak= 1/To* Integral from 0 to 2(e^(-jwt)dt)
I forgot how to solve this integral can anyone help?

5. ### GirishC Active Member

Jan 23, 2009
58
0
ak = (1/T0) <0> I <2> e^-jwt dt
= (1/T0)* [(1/-jw)* e^-jwt] <0> to <2>
= (1/-jwT0) [e^0 + e^-2jw]

and you can solve further to get cosine and sine terms