Question

please help help help help help help help help help help help help help help help help help help help help help help help help help help help help​

Answer 1

cos 2a = cos 2 = 30° = cos 60°

cos ²a - sin²a = ( cos ²30° ) - ( sin ²30°)

( root over 3 /2 ) ² - ( 1/2)²

3/4-1/4

2/4 = 1/2

2 cos ² a = 2 cos ² 30° - 1

2×(root over 3/2) ² - 1

2×3/4-1 cut 4 and 2

3 - 2 /2 = 1/2

Answer 2

Answer:

thanks so much for mark me aas brain list answer