Trigonometry Examples

$\frac{\cos (x + h) - \cos (x)}{h}$

Step 1

Apply the sum of angles identity $\cos (x + y) = \cos (x) \cos (y) - \sin (x) \sin (y)$ .

$\frac{\cos (x) \cos (h) - \sin (x) \sin (h) - \cos (x)}{h}$