%	c4ex2 MATLAB application%syms t w f 									% Define symbolic variablesx = sym('exp(-2*t)*Heaviside(t)')	% Symbolically define signalX = fourier(x)								% Symbolically take the Fourier transformXf = subs(X, 'w', sym('2*pi*f'))		% Change independent variable to f = w/(2*pi) in hertzXf_conj = subs(Xf, 'f' ,sym('-f'))	% Conjugate Fourier transformGf = symmul(Xf, Xf_conj)				% Multiply the Fourier transform and its conjugateezplot(Gf)									% Use the ezplot routine to plot energy spectrum