JEE PYQ: Differentiation Question 14
Question 14 - 2019 (08 Apr Shift 2)
If $f(1) = 1$, $f’(1) = 3$, then the derivative of $f(f(f(x))) + (f(x))^2$ at $x = 1$ is:
(1) $33$ (2) $12$ (3) $15$ (4) $9$
Show Answer
Answer: (1) $33$
Solution
$g’(1) = f’(1)^3 + 2f(1)f’(1) = 27 + 6 = 33$.