Any MATLAB Filter that changes cosine to sine?

[testing test]

Hi,

I have a cosine input and I want it to multiply with a filter which changes the cosine to sine. The following code just plots a cosine signal. I want to multiple x with impulse response of a filter such that the output is a sine signal. Please help me design any such filter via coding.

N=100;
t=0:N;
f1=20;
fs=300;
x=cos(2*pi*f1/fs*t);
plot(t,x);

Thank you!

 

[RBB]

I would take advantage of the fact that
sin(x) = -dcos(x)/dt
The filter is then a simple differentiator...
y[n] = x[n] - x[n-1];

 

[testing test]

Can you please give me a few lines of MATLAB code for implementation of this filter?

 

[RBB]

y = filter([1, -1], 1, x);