Question
Evaluate the following integrals:
$\int\cos^{-1}(4\text{x}^3-3\text{x})\text{dx}$

Answer

Let $\text{I}=\int\cos^{-1}(4\text{x}^3-3\text{x})\text{dx}$
Let $\text{x}=\cos\theta$
$\text{dx }=-\sin\theta\text{d}\theta$
$\text{I}=-\int\cos^{-1}(4\cos^3\theta-3\cos\theta)\sin\theta\text{d}\theta$
$=-\int\cos^{-1}(\cos3\theta)\sin\theta\text{d}\theta$
$=-\int3\theta\sin\theta\text{d}\theta$
$=-3[\theta\int\sin\theta\text{d}\theta-\int(1\int\sin\theta\text{d}\theta)\text{d}\theta]$
$=-3[-\theta\cos\theta+\int\cos\theta\text{d}\theta]$
$=3\theta\cos\theta-3\sin\theta+\text{C}$
$\text{I}=3\text{x}\cos^{-1}\text{x}-3\sqrt{1-\text{x}^2}+\text{C}$

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

Similar questions

Maximise Z = x + 2y
subject to the constraints
$\text{x + 2y} \geq 100\\ \text{2x - y} \leq 0\\ \text{2x + y} \leq 200\\ \text{x, y} \geq 0$
Solve the above LPP graphically.
Find a particular solution of the differential equation $ \frac { d y } { d x } + y \cot x = 4 x \; cosec \; x$, x $\neq$ 0 given that y = 0, when $ x = \frac { \pi } { 2 }$.
Discuss the continuity and differentiability of $\text{f(x)}=\text{e}^{|\text{x}|}.$
Find the inverse of the following matrices and verify that A-1 A = I3.
$\begin{bmatrix}1 & 3 & 3 \\ 1 & 4 & 3 \\ 1 & 3 & 4 \end{bmatrix}$
Show that the function f defined as follows, is continuous at x = 2, but not differentiable thereat:
f(x) = $\begin{matrix} \text{3x - 2}, && 0<x\leq1 \\ \text{ 2x}^{2}-\text{x}, && 1<x\leq2 \\ \text{5x - 4}, && x>2 \end{matrix}$.
Evaluate the following integrals:
$\int\limits^{1}_0\frac{\log(1+\text{x})}{1+\text{x}^2}\text{ dx}$
Evaluate the following integrals:
$\int\limits^{\frac{\pi}{3}}_{\frac{\pi}{6}}\frac{\sqrt{\sin\text{x}}}{\sqrt{\sin\text{x}}+\sqrt{\cos\text{x}}}\text{ dx}$
An experiment succeeds twice as often as it fails. Find the probability that in the next 6 trials there will be at least 4 successes.
Prove that the function
$\text{f}\text{(x)}=\begin{cases}\frac{\text{x}}{|\text{x|+2}\text{x}^2}, &\text{ x}\neq0\\\text{k}, &\text{ x}=0\end{cases}$ 
remains discontinuous at x = 0, regardless the choice of k.
Find a unit vector perpendicular to each of the vectors $\overrightarrow{\text{a}}+ \overrightarrow{\text{b}}$ and $\overrightarrow{\text{a}}- \overrightarrow{\text{b}},$ where $\overrightarrow{\text{a}}=3\hat{\text{i}}+2\hat{\text{j}}+2\hat{\text{k}}$ and $\overrightarrow{\text{b}}=\hat{\text{i}}+2\hat{\text{j}}-2\hat{\text{k}}.$