Решение произвольные?

Решите задачу:

$f(x)=5x^6-2x-4,5\\f'(x)=30x^5-2\\\\f(x)=\frac3{x^9}-\frac{x^8}4+4\sqrt x\\f'(x)=-\frac{27}{x^{10}}-2x^7+\frac2{\sqrt x}\\\\f(x)=\sin x(3-x^2)\\f'(x)=\cos x(3-x^2)-2x\sin x\\\\f(x)=\frac{x+6}{\cos x}\\f'(x)=\frac{\cos x+(x+6)\sin x}{\cos^2x}\\\\f(x)=(3x^3-1)(x+2)\\f'(x)=3x^2(x+2)+(3x^3-1)=3x^3+6x^2+3x^3-1=6x^3+6x^2-1\\\\f(x)=(2x^8-3)^{15}\\f'(x)=15(2x^8-3)^{14}\cdot16x^7=240x^7(2x^8-3)^{14}\\\\f(x)=\sin2x\\f'(x)=3\cos3x$