The question is from Integral Transform For Engineers By Andrews and Shivamoggi.
Evaluate the Mellin transform of the given function. When possible, use known integral results from previous chapters.
$1.f(x)=h(a-x)$ $a>0$
I started as $M${$h(x-a),s$}=$$\int_{0}^{\infty}x^{s-1}h(x-a)dx=\int_{a}^{\infty}x^{s-1}dx=\frac{x^s}{s}\Big|_a^\infty $$
But the resultant answer will be infinity.I know this is not correct.Please tell me how to do this.