Determine Where the Function Is Increasing and Where It Is $$f ( x ) = x ^ { 2 } - 8 x$$

Multiple Choice

Determine where the function is increasing and where it is decreasing.
- $$f ( x ) = x ^ { 2 } - 8 x$$

A) increasing on $( - \infty , 4 )$
decreasing on $( 4 , \infty )$

B) increasing on $( - \infty , - 4 )$
decreasing on $( - 4 , \infty )$

C) increasing on $( 4 , \infty )$
decreasing on $( - \infty , 4 )$

D) increasing on $( - 4 , \infty )$
decreasing on $( - \infty , - 4 )$