Question

Find the derivative of f(x) = negative 9 divided by x at x = -4. (6 points) 4 divided by 9 16 divided by 9 9 divided by 16 9 divided by 4

Answer 1

9/16

Explanation:

Answer 2

9/16

Explanation:

`f(x)=-(9)/(x)`

`f(x)=-9x^(-1)`

Derivative rule:

`f(x)=x^(n) \\`

`(df)/(dx)=nx^(n-1)`

Here, n=-1, so

`(df)/(dx)=(-9)(-1)x^(-2) =(9)/(x^(2) )`

Evaluating this at x=-4 gives 9/16