# What is the derivative of 4/x?

$- \frac{4}{x} ^ 2$
Use the rule that $\frac{d}{\mathrm{dx}} \left[{x}^{n}\right] = n {x}^{n - 1}$.
Also, recall that $\frac{4}{x} = 4 {x}^{-} 1$.
Thus, d/dx[4x^-1]=(4)(-1)x^(-1-1)=-4x^-2=color(blue)(-4/x^2