# 3d fourier transform

Hi, just got set a 3d fourier transform to solve but I've never seen one before and cant find any examples online. once the integral is set up I should be fine but I'm not sure how to set it up;

What is fourier transfrom (f(k)) of following 3d function for k=(kx, ky, kz)=(1,2,3)

for f(x,y,z) = 1 if mod(x)<1,mod(y)<1,mod(z)<1 and f(x,y,z)=0 otherwise

Im just struggling how to set up the integral, I assume I have to do a triple integral, but Im not sure whether I have to simply integrate from -1 to 1 for x,y and z (here Im not sure what to do with whats normally e^(-ikx))....or whether I have to convert to spherical co-ordinates.

any help would be greatly appreciated