(a) Given $5 x ^ { 3 } + 40 = \int _ { C } ^ { X } f ( t ) d t$. (i) Find $f ( x )$. (ii) Find the value of $c$. (b) If $F ( x ) = \int _ { x } ^ { 3 } \sqrt { 1 + t ^ { 16 } } d t$, find $F ^ { \prime } ( x )$.
& 10.8
(a) Given $5 x ^ { 3 } + 40 = \int _ { C } ^ { X } f ( t ) d t$.
(i) Find $f ( x )$.
(ii) Find the value of $c$.
(b) If $F ( x ) = \int _ { x } ^ { 3 } \sqrt { 1 + t ^ { 16 } } d t$, find $F ^ { \prime } ( x )$.