Given that csctheta=-8/5cscθ=85 where pi<theta<(3pi)/2π<θ<3π2, how do you determine the exact value of tanthetatanθ?

1 Answer
Jun 7, 2017

tan theta = 5/sqrt39tanθ=539

Explanation:

csc theta = -8/5 :. sin theta = -5/8 ; pi < theta <(3pi)/2, theta is in third quadrant. Let P = perpendicular of rt triangle , H=hypotenuse of a rt. triangle and B= base of rt.triangle.

Sin theta = P/H :. P = -5 ; H=8 :. B= sqrt(H^2-P^2)= sqrt(64-25)=+-sqrt39 = -sqrt39 In 3 rd quadrant both P and B are negative.

:. tan theta = P/B = (-5)/-sqrt39 = 5/sqrt39 [Ans]