f(x)=9x^4-3x^2+5sin(x)+tg(x)
f ' (x) =4*9*x^3-2*3*x+5cos(x)+1/cos^2(x) =
=36x^3-6x+5cos(x)+1/cos^2(x)
f(x)=9x^4-3x^2+5sin(x)+tg(x)
f ' (x) =4*9*x^3-2*3*x+5cos(x)+1/cos^2(x) =
=36x^3-6x+5cos(x)+1/cos^2(x)