1.is this correct
2.
3.
1) sin(-x) = -sin(x)
tan(-x) = -tan(x)
sin(-x) · tan(-x) = -sin(x) · -tan(x) = sin(x) · tan(x)
I dont understand is it not correct
sin (- θ) = -sin θ
tan (-θ) = - tan θ
So we have
(-sin θ) ( -tan θ)
_____________ =
sec θ
sin θ (sin θ / cos θ)
________________ =
1 / cos θ
sin^2 θ
Second one
We can use the Law of Cosines, here
distance = √ [ 60^2 + 115^2 - 2 ( 60)(115) cos (130°) ] = √ 25695 ≈ 160.3 ft
Last one
7 revs = 14 pi rads
Distance / Rate = Time
14 pi 14
_________ = ______ = 14 (9 / 32) ≈ 3.9 min
(32/ 9) pi (32/9)