*Exercise 17.5 Use contour integration to compute the Fourier transform of f(x) = e-az?, a > 0. Hint: It is sufficient to compute f(s) for & > 0, since is even (Proposition 17.2.3). Consider the contour rr formed by the lines joining -R to R, R to R+ , R+ to -R+ , and -R+&to - R. By Cauchy's formula, Sr. e-ar dz = 0. Let R tend to +oo to show that f(E) = e . *Exercise 17.5 Use contour integration to compute the Fourier transform of f(x) = e-az?, a > 0. Hint: It is sufficient to compute f(s) for & > 0, since is even (Proposition 17.2.3). Consider the contour rr formed by the lines joining -R to R, R to R+ , R+ to -R+ , and -R+&to - R. By Cauchy's formula, Sr. e-ar dz = 0. Let R tend to +oo to show that f(E) = e