If in doubt, \(k\cos (x - \alpha )\) usually works. These worked examples show the processes you'll need to go through to rewrite an expression in this form. Write \(2\sin x^\circ + 5\cos x^\circ ...

\(\frac{{dy}}{{dx}} = \frac{{dy}}{{du}} \times \frac{{du}}{{dx}}\) \(\frac{{dy}}{{dx}} = \frac{1}{2}{(u)^{ - \frac{1}{2}}} \times (4x + 3)\) \(\frac{{dy}}{{dx ...