# Math Help - Slope of a line tangent

1. ## Slope of a line tangent

Find the slope of a line tangent to the curve $y = \frac{4}{x^2} - 2x^2$ at $(-1, 2)$

My Work:

$\frac{f'(x)g(x) - f(x)g'(x)}{g(x)^2}$

$\frac{-8x}{x^4} - 4x$

$m = 12$

Hows it look?

2. Hello,

Originally Posted by R3ap3r
Find the slope of a line tangent to the curve $y = \frac{4}{x^2} - 2x^2$ at $(-1, 2)$

My Work:

$\frac{f'(x)g(x) - f(x)g'(x)}{g(x)}$

$\frac{-8x}{x^4} - 4x$

$m = 12$

Hows it look?
It looks Ok

Just a remark :

$\frac{4}{x^2}=4 \cdot \frac{1}{x^2}$

A derivative of $\frac{1}{x^2}=x^{-2}$ is $-2 x^{-3}=\frac{-2}{x^3}$