Question

cos^4A - sin^4A is equal to:
(a) 2cos^2A+1
(b) 2cos^2A-1
(c) 2sin^2A-1
(d) 2sin^2A+1

i need step by step answer.​

Answer 1

Answer:

b) 2cos^2A-1

Step-by-step explanation:

hope this helps!

:D