Answer:
Below.
Step-by-step explanation:
I'll write sin x as s and cos x as c so we have:
(1 + s +c)/(1 + s - c) = (1 + c)/s
Cross multiplying:
s + s^2 + cs = 1 + s - c + c + cs - c^2
s + s^2 + cs = 1 + s + cs - c^2
s^2 + c^2 + s - s + cs - cs = 1
s^2 + c^2 = 1.
- that is sin^2 x + cos^2 x = 1 which is a known identity.
Therefore the original identity is proved.
