Use the Definition of Derivative $\lim _ { z \rightarrow c } \frac { f ( z ) - f ( c ) } { z - c }$

Short Answer

Use the definition of derivative: $\lim _ { z \rightarrow c } \frac { f ( z ) - f ( c ) } { z - c }$ to find $f ^ { \prime } ( - 1 ) \text {, if } f ( x ) = x ^ { 2 }$