Y=(XSQUARE + 1

OVER
XSQUARE - 1) CLOSE PARENTHESIS TO THE 3 POWER...

y = [(x^2+1) /(x^2-1) ]^3 ???

what do you want, the derivative?
if so

dy/dx = 3[(x^2+1) /(x^2-1) ]^2 * { (x^2-1)2x -(x^2+1)2x}/ (x^2-1)^2

etc, multiply out and simplify