Find the Intervals of Increase and Decrease for the Function $f ( x ) = x ^ { 2 } + 9 x - 4$

Multiple Choice

Find the intervals of increase and decrease for the function $f ( x ) = x ^ { 2 } + 9 x - 4$ .

A) $\text { Decreasing for } x > - \frac { 9 } { 2 } \text { and increasing for } x < - \frac { 9 } { 2 }$
B) $\text { Decreasing for } x < - \frac { 9 } { 2 } \text { and increasing for } x > - \frac { 9 } { 2 }$
C) Decreasing for all x
D) Increasing for all x