Answer:
hence cos ( 2 A ) = cos 2 A − ( 1 − cos 2 A ) = 2 cos 2 A − 1
Step-by-step explanation:Well we know that for two angles A , B
it holds that cos ( A + B ) = cos A cos B − sin A ⋅ sin B hence for A = B you get cos ( 2 A ) = cos 2 A − sin 2 A But sin 2 A = 1 − cos 2 A
15/60 simplified is 1/4
1/4 is not equal to 3/4
4-6= -2 what are you having problems understanding I can help
