DSB-SC Signal from Homework Statement

[Cocoleia]

Homework Statement

I am giving the following signal:

and asked to get the DSB-SC signal of this

Homework Equations

3. The Attempt at a Solution [/B]
So, I know a few things.

My prof writes that

I would have to multiply my original signal out and then take the Fourier transforms accordingly ?
Yet, another source suggests:

I was trying to multiply it out to get
m^2(t)+2m(t)Accos(2pifct)+Ac^2cos^2(2pifct)
then I would have to take the Fourier transform but set it to f-fc. I would be unsure how to proceed with the m^2(t), so I feel like i am doing something wrong

 

[tnich]

Homework Statement

I am giving the following signal:
View attachment 222006
and asked to get the DSB-SC signal of this

Homework Equations

3. The Attempt at a Solution [/B]
So, I know a few things.

My prof writes that
View attachment 222007
I would have to multiply my original signal out and then take the Fourier transforms accordingly ?
Yet, another source suggests:
View attachment 222008

I was trying to multiply it out to get
m^2(t)+2m(t)Accos(2pifct)+Ac^2cos^2(2pifct)
then I would have to take the Fourier transform but set it to f-fc. I would be unsure how to proceed with the m^2(t), so I feel like i am doing something wrong

Please use LaTeX to write your equations. (See https://www.physicsforums.com/help/latexhelp/.) It makes them much easier to read and greatly increases the likelihood that you will receive replies to your posts.
Won't ##m^2(t)## have a DC bias? Can you make use of that bias?