Establish the identity 1 cos2 theta1 sin theta sin theta
     Establish the identity.  1 - cos^2 theta/1 + sin theta = sin theta  Simplify the numerator of the fraction from the left side by applying the appropriate Pythagorean Identity.  1 - squarebox/1 + sin theta (Do not factor.)  Factor the numerator of the fraction from the previous step.  1 - squarebox/1 + sin theta  The expression from the previous step then simplifies to sin theta using what? 
  
  Solution
1 - [cos2/(1 + sin)] = sin
LHS = 1 - [cos2/(1 + sin)] = 1 - [(1 - sin2)/(1 + sin)] = 1 - [(1 - sin)(1 + sin)/(1 + sin)]
= 1 - (1 - sin) = sin = RHS

