The function x^4 - 4x is decreasing in the interval - Vidyadip

MCQ

The function ${x^4} - 4x$ is decreasing in the interval

A
$[-1, 1]$
✓
$( - \infty ,\,\,1)$
C
$[1,\,\, + \infty )$
D
None of these

✓

Answer

Correct option: B.

$( - \infty ,\,\,1)$

b
(b) Let $f(x) = {x^4} - 4x \Rightarrow f'(x) = 4{x^3} - 4$

So, $4{x^3} - 4 < 0$ or ${x^3} < 1$

Hence function of decreasing in $( - \infty ,1)$.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from STD 12 - 6. Application of derivatives→STD 12 - 6. Application of derivatives — all question types→Mathematics STD 12 Science question papers→CBSE Board STD 12 Science question papers→CBSE Board question paper generator→

Similar questions

If a line makes angle $\alpha,\beta$ and $\gamma$ with the axes respectively, then $\cos2\alpha+\cos2\beta+\cos2\gamma=$

If x, y, z are nonzero real numbers, then the inverse of matrix $\text{A}=\begin{bmatrix}\text{x}&0&0\\0&\text{y}&0\\0&0&\text{z}\end{bmatrix}$ is

If $y = {\cot ^{ - 1}}\left[ {{{\sqrt {1 + \sin x} + \sqrt {1 - \sin x} } \over {\sqrt {1 + \sin x} - \sqrt {1 - \sin x} }}} \right]$, then ${{dy} \over {dx}} = $

Which of the following is a homogeneous differential equation?

The value of the integral $\sum\limits_{k = 1}^n {\int_0^1 {f(k - 1 + x)\,dx} } $ is

If $A = \left[ {\begin{array}{*{20}{c}}2&{ - 3}\\{ - 4}&1\end{array}} \right],$ then $adj\;\left( {3{A^2} + 12A} \right) = $ . . . .

$\int_{\frac{-\pi}{4}}^{\frac{\pi}{4}}\frac{\text{dx}}{1+\cos2\text{x}}\text{dx}$ is equal to:

Let R be a relation on the set N of natural numbers defined by nRm if n divides m. Then, R is:

Let $\sin\text{y}=\text{x}\sin(\text{a}+\text{y}),$ then $\frac{\text{dy}}{\text{dx}}$ is:

$\int\frac{\cos2\text{x}-\cos2\theta}{\cos\text{x}-\cos\theta}\text{ dx}$ is equal to: