Show that the $1-$D convolution theorem given in

Eqs. $(4-25)$ and $(4-26)$ also holds for discrete vari$-$

ables, but with the right side of Eq$.(4-26)$ multi$-$

plied by $\frac{1}{M}.$ That is$,$ show that

$($a$)*(f***h)(x)>(F*H)(u),$ and

$($b$)(f*h)(x)>\frac{1}{M}(F***H)(u)$