Evaluate $\int_{-1}^{2}\left|x^{3}-x\right| d x$

Vedclass pdf generator app on play store
Vedclass iOS app on app store
(D) We note that $x^{3}-x \geq 0$ on $[-1,0]$,$x^{3}-x \leq 0$ on $[0,1]$,and $x^{3}-x \geq 0$ on $[1,2]$.
Using the property of definite integrals,we split the interval:
$\int_{-1}^{2} |x^{3}-x| dx = \int_{-1}^{0} (x^{3}-x) dx + \int_{0}^{1} -(x^{3}-x) dx + \int_{1}^{2} (x^{3}-x) dx$
$= \int_{-1}^{0} (x^{3}-x) dx + \int_{0}^{1} (x-x^{3}) dx + \int_{1}^{2} (x^{3}-x) dx$
$= \left[ \frac{x^{4}}{4} - \frac{x^{2}}{2} \right]_{-1}^{0} + \left[ \frac{x^{2}}{2} - \frac{x^{4}}{4} \right]_{0}^{1} + \left[ \frac{x^{4}}{4} - \frac{x^{2}}{2} \right]_{1}^{2}$
$= [0 - (\frac{1}{4} - \frac{1}{2})] + [(\frac{1}{2} - \frac{1}{4}) - 0] + [(4 - 2) - (\frac{1}{4} - \frac{1}{2})]$
$= -(-\frac{1}{4}) + (\frac{1}{4}) + (2 - (-\frac{1}{4}))$
$= \frac{1}{4} + \frac{1}{4} + 2 + \frac{1}{4} = \frac{3}{4} + 2 = \frac{11}{4}$

Explore More

Similar Questions

If $\cos x + \cos 2x + \ldots + \cos nx = \frac{A(x)}{2 \sin(x/2)}$, then $\int_0^\pi A(x) dx =$

The area of the region under the graph of $y = xe^{-ax}$ as $x$ varies from $0$ to $\infty$,where $'a'$ is a positive constant,is

$\int_0^{\pi /4} (\cos x - \sin x) dx + \int_{\pi /4}^{5\pi /4} (\sin x - \cos x) dx + \int_{2\pi }^{\pi /4} (\cos x - \sin x) dx$ is equal to

Difficult
View Solution

The integral $\int_{1}^{e} \left( \left( \frac{x}{e} \right)^{2x} - \left( \frac{e}{x} \right)^{x} \right) \log_{e} x \, dx$ is equal to

If $\int_{0}^{k} \frac{dx}{2 + 18x^2} = \frac{\pi}{24}$,then the value of $k$ is

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo