Fourier transforms of a box function and a one-sided exponential

Calculate the Fourier image \(\tilde { f } ( \boldsymbol { k } )\) of the function f (x), if f (x) is given by

1. \(f ( x ) = { \left\{ \begin{array} { l l } { f _ { 0 } , | x | \leqslant x _ { 0 } , } \\ { 0 , | x | > x _ { 0 } } \end{array} \right. }\)

2. \(f ( x ) = \left\{ { \begin{array} { l } { e ^ { - a x } , x \geqslant 0 , a > 0 , } \\ { 0 , x < 0 } \end{array} } \right.\)