Question

sin^4A-cos^4A=1-2cos^2A​

Answer 1

Answer:

mark me as brainliest

Step-by-step explanation:

sin^4A-cos^4A = ( sin^2 A + cos^2 A )( sin^2 A - cos^2 A )

= 1 ( 1 - cos^2 A - cos^2 A )

= 1 - 2 cos^2 A