How to work out convolute in frequency domain?

Hi there. First of all,I'm very new to Matlab (more then I should be actually).So take it easy on me. Anyway : I need to convolute two signals,they both are in frequency domain . The thing is : One of them is sin function ,which is translated in frequency domain to two Dirac functions. Second one is given in graphical form.

I need to compute the convolution ,and have the graph of it. How on earth do I do that ?

Here are the two signals I need to convolute :

http://imgur.com/4j6efXh

The bottom one is the sine [its transform of sin(w0*t/2),so the height of the deltas are pi and -pi] ,the upper one is given to me .

Thanks in advance.

[kjetil87]

A hint: http://en.wikipedia.org/wiki/Convolution_theorem

Answer 1

[Jake]

Yes,I know its convolution :) (that's what I asked),and I know how to do it manually . I'm asking how can I compute the convolution of those two,when one of them is given non explicitly ,and the other is two Dirac functions,using MATLAB - I need the plot .

Thanks.

[kjetil87]

Well, few people have an interest in simply doing your task. Maybe you need to be more specific about your problem? Did you read the part that says that convolution in the time domain is the same as multiplication in the frequency domain? Is your problem, creating the fft? multpiplying them? Try these functions

help fft
help ifft
help mtimes
help conv