Make the given substitution to evaluate the indefinite integral.

Integral from nothing to nothing$1616$cosecant squared left parenthesis $8$ x right parenthesiscsc$2(8$x$)$cotangent left parenthesis $8$ x right parenthesiscot$(8$x$)$dx$,$

$$a$.$

uequals$=$cotangent left parenthesis $8$ x right parenthesiscot$(8$x$),$

$$b$.$

uequals$=$cosecant left parenthesis $8$ x right parenthesis