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:
0.666666667
Step-by-step explanation:
Answer:
-a^2 - a + 12
Step-by-step explanation:
You only need to find the products of the first and last terms to determine the correct answer:
(-a)(a) = -a^2
(3)(4) = 12
You're looking for an expression with -1 as the leading coefficient and +12 as the constant. There is only one choice like that:
-a^2 - a + 12
It's 3/4 because (y2-y1)/(x2-x1)
