45+-17
This is the same as subtracting 17 from 45
45-17=28
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
His score was 40 each question was worth 5 points
Answer:
Denote AH as height of triangle ABC, with H lies on BC.
Applying sine theorem:
AH/AC = sin 60
=> AH = AC x sin 60 = 47 x sqrt(3)/2 = 40.7
=> Area of triangle ABC is calculated by:
A = AH x BC x (1/2) = 40.7 x 30 x (1/2) = 610.5 = ~611
=> Option C is correct.
Hope this helps!
:)
