$$\text { Find the value of } \mathrm { df } ^ { - 1 } / \mathrm { dx } \text { at } x = f ( a ) \text {. }$$

Multiple Choice

$$\text { Find the value of } \mathrm { df } ^ { - 1 } / \mathrm { dx } \text { at } x = f ( a ) \text {. }$$
- $$f ( x ) = 5 x ^ { 2 } , x \geq 0 , a = 3$$

A) 30
B) $\frac { 1 } { 30 }$
C) $\frac { 1 } { 45 }$
D) $\frac { 1 } { 10 }$