The integrating factor of differential equation $\cos x\frac{{dy}}{{dx}} + y\sin x = 1$ is

Given that, $\cos x\frac{{dy}}{{dx}} + y\sin x = 1$

$\Rightarrow$ $\frac{{dy}}{{dx}} + y\tan x = \sec x$

Here, $P = \tan x$ and $Q = \sec x$

$IF = {e^{\int P dx}} = {e^{\int {\tan } xdx}} = {e^{\log \sec x}}$

$\therefore$ $= \sec x$