Recall that sin2x + cos2x = 1. So, cos2x = 1 - sin2x.
Multiply the numerator and denominator of (sinx + cosx) / (sinx - cosx) by sinx + cosx to get:
[sin2x + 2sinxcosx + cos2x] / [sin2x - cos2x]
= [1 + 2sinxcosx] / [sin2x - (1 - sin2x)] = [1 + 2sinxcosx] / [2sin2x - 1]
Spenser G.
Ahh ok, I multiplied left side by reciprocal to start10/30/24