# Chapter 7, Asmar's textbook, Fourier Transform

# Package INTTRANS is loaded for Fourier Transform
 with(inttrans):

# Define a function
 unassign('x','t','p'):f:=x->1+x^2:

# FORWARD FOURIER TRANSFORM
 ans1:=fourier(f(x),x,p);
 ans2:=fourier(BesselJ(0,x),x,p);

# BACKWARD FOURIER TRANSFORM
 invfourier(ans1,p,t);
 invfourier(ans2,p,t);

# FOURIER SINE TRANSFORM
 fouriersin(f(t),t,p);
 fouriersin(erf(x),x,y);

# FOURIER COSINE TRANSFORM
 fouriercos(f(t),t,p);