JEE MATHEMATICS MCQ: INCREASING & DECREASING

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Analyzing +4 | -1

Consider the function

f(x)= \begin{cases}x e^{a x} & \text { for } x \leq 0 \\ x+a x^2-x^3 & \text { for } x>0\end{cases}

where

a>0

is constant. Then

f^{\prime}(x)

View answer and explanation

Correct option: A

increasing in

\left(\frac{-2}{a}, \frac{a}{3}\right)

Option A is correct because the second derivative of the function is positive in the interval (-2/a, a/3), indicating that the first derivative is increasing in that interval.

More Questions from INCREASING & DECREASING

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If the function

f\left( x \right) = \frac{{K\sin x + 2\cos x}}{{\sin x + \cos x}}

is increasing for all values of

x

, then The set of values of a for which the function

f\left( x \right) = {x^2} + ax + 1

is an increasing function on [1,2] is The value of

a

in order that

f(x)=

\sin x-\cos x-a x+b

decreases for all real values is given by The function

f(x)=x e^{x(1-x)}, x \in R

, is If

f

and

g

are two increasing functions such that

fog

is defined, then If

f\left( x \right) = {x^3} + b{x^2} + cx + d

and

0 < {b^2} < c

, then in

\left( { - \infty ,\;\infty } \right)