Find the Vertex of the Graph of the Quadratic Function $$f ( x ) = x ^ { 2 } + x - 1$$

Multiple Choice

Find the vertex of the graph of the quadratic function.
- $$f ( x ) = x ^ { 2 } + x - 1$$

A) $( - 1 , - 1 )$
B) $( 1,1 )$
C) $\left( - \frac { 1 } { 2 } , - \frac { 5 } { 4 } \right)$
D) $\left( \frac { 1 } { 2 } , - \frac { 1 } { 4 } \right)$