Q75 / 155 · WBJEE 2025 · Mathematics
Let $f$ be a function which is differentiable for all real $x$. If $f(2)=-4$ and $f^{\prime}(x) \geq 6$ for all $x \in[2,4]$
- A$f(4) \lt 8$
- B$f(4) \geq 12$
- Correct answerC$f(4) \geq 8$
- D$f(4) \lt 12$
Solution
By LMVT
$f^{\prime}(x)=\frac{f(4)-f(2)}{4-2}$
as $f^{\prime}(x) \geq 6 \Rightarrow f(4) \geq 8$
Hence, the correct answer is option: 'C'.