Trigonometry Identities - Power Reducing to Identity (Greek Letter)

Question

Complete the power reducing identity for this expression

$$	ext{tan}^2{(\alpha)}$$

Accepted Answer

$$=\frac{1-	ext{cos}(2\cdot\alpha)}{1+	ext{cos}(2\cdot\alpha)}$$

Answer

$$=\frac{1+	ext{cos}(2\cdot\alpha)}{2}$$