Evaluate the following integrals:
$\int \frac{\sin ^{3} x}{\sqrt{\cos x}} d x$
In this equation, we can manipulate numerator
$\sin ^{3} x=\sin ^{2} x \cdot \sin x$
$\therefore$ Now the equation becomes,
$\Rightarrow \int \frac{\sin ^{2} x \cdot \sin x}{\sqrt{\cos x}} d x$
$\sin ^{2} x=1-\cos ^{2} x$
$\Rightarrow \int \frac{1-\cos ^{2} x \cdot \sin x}{\sqrt{\cos x}} d x$
Now,
Let us assume $\cos x=t$
$\mathrm{d}(\cos x)=\mathrm{dt}$
$-\sin x d x=d t$
Substitute values of $\mathrm{t}$ and $\mathrm{dt}$ in above equation
$\Rightarrow-\int \frac{1-t^{2}}{\sqrt{t}} d t$
$\Rightarrow-\int \frac{1}{\sqrt{t}} d t-\int \frac{t^{2}}{\sqrt{t}} d t$
$\Rightarrow-\int t^{-1 \backslash 2} d t+\int t^{3} \backslash^{2} d t$
$\Rightarrow-2 t^{1 \backslash 2}+\frac{2}{5} t^{\frac{5}{2}}+c$
But $t=\cos x$
$\Rightarrow-2 \cos x^{1 \mid 2}+\frac{2}{5} \cos x^{\frac{5}{2}}+c$