Evaluate: `intcossqrt(x)\ dx`

Explanation

`I=\int \cos \sqrt{x} d x`


Put `\sqrt{x}=t` so that `\frac{1}{2 \sqrt{(x)}} d x=d t \therefore I=f(\cos t) 2 t d t=2 \int t \cos t d t`



Integrating by parts, we get `I=2[t \sin t-\int 1 \cdot \sin t d t]`



...