Given the Fourier Transform pairs below, find the Fourier transform for each signal.
e^(-bt)u(t)harr(1)/(j omega +b), where b>0
(a) x_(1)(t)=e⁽⁻⁵ᵗ⁾e⁽ʲ²ᵗ⁾u(t)
(b) x_(2)(t)=e⁽⁻⁵ᵗ⁾cos(2t)u(t)