Question
Evaluate the following integrals:
$\int^\limits{\pi}_{0}5\big(5-4\cos\theta\big)^{\frac{1}{4}}\sin\theta\text{ d}\theta$

Answer

Let $\text{I}=\int^\limits{\pi}_{0}5\big(5-4\cos\theta\big)^{\frac{1}{4}}\sin\theta\text{ d}\theta$
Let $\big(5-4\cos\theta\big)=\text{t}$ Then, $4\sin\theta\text{ d}\theta=\text{dt}$
When $\theta=0,\text{t}=1$ and $\theta=\pi,\text{t}=9$
$\therefore\ \text{I}=\frac{5}{4}\int\limits^9_1\text{t}^{\frac{1}{4}}\text{ dt}$
$\Rightarrow\text{I}=\frac{5}{4}\Bigg[\frac{4\text{t}^{\frac{5}{4}}}{5}\Bigg]^9_1$
$\Rightarrow\text{I}=\big(9\sqrt{3}-1\big)$

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

Prove that: $\cos ^{-1} \frac{12}{13}+\sin ^{-1} \frac{4}{5}=\tan ^{-1} \frac{63}{16}$
Prove that: $\int_0^\pi \frac{x}{1-\cos \alpha \sin x} d x=\frac{\pi(\pi-\alpha)}{\sin \alpha}$
If A and B are square matrices of the same order such that $AB = BA,$ then prove by induction that $AB’’ = B’’A.$ Further prove that $(AB)’’ = A’’B’’$ for all $n \Rightarrow N.$
Differentiate the following functions with respect to x:
$3^{\text{x}^2+2\text{x}}$
Find the general solution of the differential equation
$x\left(y^3+x^3\right) d y=\left(2 y^4+5 x^3 y\right) d x$
Using the properties of determinants, prove that
$ \begin{vmatrix} \text{a + b} & \text{b + c} & \text{c + a} \\ \text{b + c} & \text{c + a} & \text{a + b} \\ \text{c + a} & \text{a + b} & \text{b + c} \end{vmatrix}=2 \begin{vmatrix} \text{a} & \text{b} & \text{c} \\ \text{b} & \text{c} & \text{a} \\ \text{c} & \text{a} & \text{b} \end{vmatrix}$.
Evaluate the following integrals:
$\int\frac{\sin(\log\text{x})}{\text{x}}\text{ dx}$
Solve the following differential equation :
$
\left(x^2-1\right) \frac{d y}{d x}+2 x y=\frac{1}{x^2-1},|x| \neq 1
$
Find $\Big[\vec{\text{a}}\ \vec{\text{b}}\ \vec{\text{c}}\Big]$, when
$\vec{\text{a}}=\hat{\text{i}}-2\hat{\text{j}}+3\hat{\text{k}},\vec{\text{b}}=2\hat{\text{i}}+\hat{\text{j}}-\hat{\text{k}}$ and $\vec{\text{c}}=\hat{\text{j}}+\hat{\text{k}}$
Let f be a real function given by $\text{f(x)}=\sqrt{\text{x}-2}.$ Find the following:
fofof
Also, show that fof ≠ $f^2$.