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
Answer:
Step-by-step explanation:
total degrees of a line is 180
4x+20+60=180
4x=100
X=25
Answer:
8sin(x)cos³(x)
Step-by-step explanation:
sin(4x) +2 sin(2x) = 2sin(2x)*cos(2x) + 2sin(2x) = 2sin(2x)(cos2x + 1)=
= 2sin(2x)(cos²x - sin²x + cos²x + sin²x)=²2sin(2x)*(2cos²x)=
= 4*2sin(x)*cos(x)*cos²(x)= 8sin(x)cos³(x)
