Let $f(x)=x^2+2x-1$.  

1. Evaluate and simplify $\frac { f ( 5 + h ) - f ( 5 ) } { ( 5 + h ) - 5 }$.

   Step (a):

   $\frac{(5 + h)^2 + 2(5 + h) - 1 - (5^2 + 2(5) - 1)}{h}$

2. Explain what your answer represents on the graph of $y=f(x)$.

   Hint (b):

   This is a slope expression.