Question

2.
If A + B + C = 180°, then prove that
b) cos 2A - cos 2B + cos 2C = 1 - 4 sinA cosB sin C​

Answer 1

Answer:

e modello cheyali........... ...............

Answer 2

Given:-

A+B+C= π

Require to prove:-

$cos 2A - cos 2B + cos 2C = 1 - 4 sinA cosB sin C$

Formulae required:-

Refer formula page attached.

Procedure:-

Refer solution page attached.