SOLUTION: If sinA+sinB=x and cosA+cosB=y then prove that {{{Tan (A-B)/2}}}={{{+/- √(4-x^2-y^2)/(x^2+y^2)}}}

Algebra ->  Trigonometry-basics -> SOLUTION: If sinA+sinB=x and cosA+cosB=y then prove that {{{Tan (A-B)/2}}}={{{+/- √(4-x^2-y^2)/(x^2+y^2)}}}      Log On


   

Question 1015624: If sinA+sinB=x and cosA+cosB=y then prove that Tan+%28A-B%29%2F2=%2B%2F-+%26%238730%3B%284-x%5E2-y%5E2%29%2F%28x%5E2%2By%5E2%29
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
Please correct the statement of the problem if you want it to be solved.