Question

Given cosθ = 3/5 and θ is located in the fourth quadrant; find sin 2θ

answer choices:
-24/25
-8/25
-6/25

Answer 1

Answer: -24/25

Explanation:

Answer 2

Explanation:

Sin2θ = 2sinθcosθ. We were given cosθ so that means we need to find sinθ to fill this in and get the answer.

Constructing a right triangle in QIV with 3 along the x-axis and 5 as the hypotenuse, we can find the other leg using Pythagorean's Theorem. It turns out that the other leg measures -4 (because y is negative in the fourth quadrant). Filling in our identity:

`sin(2\theta) = 2(-(4)/(5))((3)/(5))` which simplifies to