Answer:
Step-by-step 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:
[tex]sin(2\theta) = 2(-\frac{4}{5})(\frac{3}{5})[/tex] which simplifies to
