# Question #2077e

Nov 24, 2017

This can't be proved, it is not an identity.

#### Explanation:

An identity states that this is true for all $x$.

Let $x = \frac{\pi}{2}$

$2 {\sin}^{2} \left(\frac{\pi}{2}\right) + 14 \sin \left(\frac{\pi}{2}\right) \cos \left(\frac{\pi}{2}\right) + 50 {\cos}^{2} \left(\frac{\pi}{2}\right) = 26$

$2 \left(1\right) + 14 \left(1\right) \left(0\right) + 50 \left(0\right) = 26$

$2 \ne 26$

FALSE