(xⁿ)' = nx^n-1
1)f(x) = 5x
f'(x) = 5
2)f(x) = x⁴
f'(x) = 4x³
3)f(x) = x⁶/6
f'(x) = 6/6 x⁵ = x⁵
4)f(x) = 1/x² = x^-2
f'(x) = -2x^-3 = -2/x³
