Question

Sin x = 12/13; x is in Quad 2. Find exact values of sin x/2, cos x/2, tan x/2. Use Half-Angle Identities.

Answer 1

The trigonometric identity is

Here, x is second quadrant sin function has positive sign and all are negative sign.

By using Pythagorean theorem, then

Half angle formulas:

The half angle identities are