Trigonometry Identities - Double Angle to Identity (Radians)

Question

Complete the double-angle identity for this expression

$$	ext{sin}{(2\cdot\frac{7\pi}{4})}$$

Accepted Answer

$$=\frac{2	ext{tan}(\frac{7\pi}{4})}{1+	ext{tan}^2(\frac{7\pi}{4})}$$

Answer

$$=	ext{sin}(\frac{7\pi}{4})	ext{cos}(\frac{7\pi}{4})$$