Найдите производные 1)(x^2+1)/(x^2-1); 2)3 sin^2 2x; 3)(3x^3 -2x^2-5x-15)^4.

$1) y'=(( x^{2} +1)( x^{2} -1))'=( x^{4}-1)' =( x^{4})'-(1)'=4 x^{4-1}-0=4 x^{3}$

$2) y'=(3 sin^{2}2x)'=3((sin2x)^{2})'=3*2(sin2x)^{2-1}*(sin2x)'= \\ =6*sin2x*cos2x*2=6*sin4x$

3)
$y'=((3 x^{3}-2 x^{2} -5x-15)^4)'= \\ =4(3 x^{3}-2 x^{2} -5x-15)^{4-1}* (3 x^{3}-2 x^{2} -5x-15)'= \\ =4(3 x^{3}-2 x^{2} -5x-15)^{3}*(3( x^{3})'-2(x^{2})' -5(x)'-(15)')= \\ =4(3 x^{3}-2 x^{2} -5x-15)^{3}*(3*3 x^{3-1}-2*2x^{2-1}-5*1x^{1-1}-0)= \\ =4(3 x^{3}-2 x^{2} -5x-15)^{3}(9 x^{2}-4x-5 )$