Question

Sin2x-cos3x rewrite with only sin x and cos x.

Answer 1

well then, the cheap answer is
`\bf sin(2x)-cos(3x)\\\\ -----------------------------\\\\ \textit{Double Angle Identities} \\ \quad \\ \boxed{sin(2\theta)=2sin(\theta)cos(\theta)} \\ \quad \\ cos(2\theta)= \begin{cases} cos^2(\theta)-sin^2(\theta)\\ 1-2sin^2(\theta)\\ 2cos^2(\theta)-1 \end{cases} \\ \quad \\ tan(2\theta)=\cfrac{2tan(\theta)}{1-tan^2(\theta)} \\\\ and \\\\ \textit{triple angle identities} \\\\ \boxed{cos(3\theta)=4cos^3(\theta)-3cos(\theta) }`

rather obvious