Question #5fe15

1 Answer
Apr 6, 2017

sinx = 4/5sinx=45

Explanation:

Use sin^2theta + cos^2theta = 1sin2θ+cos2θ=1.

sin^2x + cos^2x = 1sin2x+cos2x=1

sin^2x + (3/5)^2 = 1sin2x+(35)2=1

sin^2x = 1 - 9/25sin2x=1925

sin^2x = 16/25sin2x=1625

sinx = +- 4/5sinx=±45

But since the angle is described as being "positive acute", it must be in the firs quadrant, and so the ratio is positive.

Practice Exercises

11. Knowing that tantheta = sintheta/costhetatanθ=sinθcosθ and sectheta = 1/costhetasecθ=1cosθ, find the value of tanthetatanθ if sectheta = 13/12secθ=1312 and sintheta > 0sinθ>0.

Solution

11. tantheta = 5/12tanθ=512

Hopefully this helps, and good luck!