How do you find the values of the six trigonometric functions given tantheta=-15/8tanθ=158 and sintheta<0sinθ<0?

1 Answer
Jan 15, 2017

sintheta=-15/17sinθ=1517, costheta=8/17cosθ=817, tantheta=-15/8tanθ=158
cottheta=-8/15cotθ=815, sectheta=17/8secθ=178, csctheta=-17/15cscθ=1715

Explanation:

As tantheta=-15/8tanθ=158 and sintheta<0sinθ<0 i.e. both are negative,

thetaθ is in Q4 - fourth quadrant and while costhetacosθ and secthetasecθ are positive, rest of the four trigonometric functions are negative.

Now as tantheta=-15/8tanθ=158, cottheta=-8/15cotθ=815 and

sectheta=sqrt(1+tan^2theta)=sqrt(1+225/64)=sqrt289/64=17/8secθ=1+tan2θ=1+22564=28964=178

:.costheta=1/sectheta=8/17

sintheta=tanthetaxxcostheta=-15/8xx8/17=-15/17

and csctheta=-17/15