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Solve the following.

Given and . Find . The Statement “ is strictly increasing in ” is false. Justify. Hence, find the…

Mathematics20254 marksNumerical
Given $f(x) = 2\log(x-2) - x^2 + 4x + 1$ and $f'(x) = \frac{-k(x-p)(x-q)}{(x-k)}$.
(a)[1.3333333333333333]
Find $k + p + q$.
(b)[1.3333333333333333]
The Statement “$f(x)$ is strictly increasing in $(-\infty, 1] \cup (2, 3]$” is false. Justify.
(c)[1.3333333333333333]
Hence, find the interval(s) in which the function is strictly increasing.

Answer

Answer (a)

Official answer key
$k + p + q = 6$.

Final answer: 6

Answer (b)

Official answer key
$f'(x) \geq 0$, $\forall x \in (-\infty, 1] \cup (2, 3]$. But domain of $f(x)$ is $x \in (2, \infty)$. $\therefore$ The Statement “$f(x)$ is strictly increasing in $(-\infty, 1] \cup (2, 3]$” is false.

Answer (c)

Official answer key
$f(x)$ is strictly increasing in $(2, 3]$.

Final answer: $(2, 3]$

Applications of Derivatives

From ISC 2025 Practice Mathematics, question 97.