HELLO,
I d be grateful to anyone who solves the following, as I have been trying for ages but it is not working.
Q/ solve by finding appropriate substitution and then integrate by parts:
integral of cos(sqrt x).
Thanks.
If $\displaystyle u=\sqrt{x}$ we have:
$\displaystyle
\int \cos(\sqrt{x})\; dx=\int \cos(u) \frac{dx}{du}\;du=2 \int u\cos(u)\;du
$
and now you use integration by parts.
(If you need more help WolframAlpha will give you a step by step explanation of the complete process)
CB