Question

ASAP Please i need this done in the next 20 minutes

cos^2B-sin^2B=3cosB+1

Answer 1

the answer is "Using the trigonometric identity

sin²x + cos²x = 1 , then sin²x = 1 - cos²x

Consider the left side

sin²a - sin²b

= (1 - cos²a) - (1 - cos²b)

= 1 - cos²a - 1 + cos²b

= cos²b - cos²a

= right side , thus verified"