# How do you find the derivative of f(x)=x^3 - 5x^2 - 4x + 20?

Nov 19, 2015

$3 {x}^{2} - 10 x - 4$

#### Explanation:

Differentiate each part separately!
Remember standard method $\frac{d}{\mathrm{dx}} \left({x}^{n}\right) = n {x}^{n - 1}$

$\frac{\mathrm{dy}}{\mathrm{dx}} = \frac{d}{\mathrm{dx}} \left({x}^{3}\right) - \frac{d}{\mathrm{dx}} \left(5 {x}^{2}\right) - \frac{d}{\mathrm{dx}} \left(4 x\right) + \frac{d}{\mathrm{dx}} \left(20\right)$

$\frac{\mathrm{dy}}{\mathrm{dx}} = 3 {x}^{2} - 10 x - 4 + 0$