Ask a New Question
Menu

If A + B + C = 180° prove that

cos2A + cos2B – cos2C = -1 -4cosAcosBcosC

Similar Questions
  1. If A + B + C = 180°, Prove thatCos²A + Cos²B + Cos²C = 1-2cosAcosBcosC
    1. answers icon 2 answers
  2. If A + B + C = 180°, Prove thatCos²A + Cos²B - Cos²C = 1 – 2sinAsinBcosC
    1. answers icon 1 answer
    1. answers icon 1 answer
  4. Prove the identities1. cos3Ɵ + cos Ɵ = 4cos^Ɵ - 2 cos Ɵ 2. sin (A+B)sin (A-B)=cos2B + sin^2 A-1
    1. answers icon 1 answer
more similar questions