((2*x-7)^8)'=16*(2*x-7)^7,
((9*x+5)^4)'=36*(9*x+5)^3,
(1/(5*x+1)^3)'=-15/(5*x+1)^4,
(1/(6*x-1)^5)'=-30/(6*x-1)^6,
(x^3*sin(2*x))'=3*x^2*sin(2*x)+2*x^3*cos(2*x),
(cos(3*x)/x)'=-3*sin(3*x)/x-cos(3*x)/x^2,
(sin(x)^2)'=2*sin(x)*cos(x)=sin(2x),
(sin(3*x)*cos(3*x))'=3*cos(3*x)^2-3*sin(3*x)^2=3cos(6x),
(cos(2*x)*sin(x)+sin(2*x)*cos(x))'=-3*sin(2*x)*sin(x)+3*cos(2*x)*cos(x),
(sin(x)^2+cos(x)^2)'=0