f(x)=x^2 -2x + cos x , f'(x) = 2x - 2 -Sinx
f(x)=x^3 + 3x-sin x , f'(x) = 3x^2 +3 -Cosx
f(x)=3x^4-7x^2 +1 , f'(x) = 12x^3 -14x
f(x)=2x^5 + 4 x^3 -3x+8, f'(x) = 10x^4 +12x^2 -3
f(x)=x^2 -2x + cos x , f'(x) = 2x - 2 -Sinx
f(x)=x^3 + 3x-sin x , f'(x) = 3x^2 +3 -Cosx
f(x)=3x^4-7x^2 +1 , f'(x) = 12x^3 -14x
f(x)=2x^5 + 4 x^3 -3x+8, f'(x) = 10x^4 +12x^2 -3