Given that cos theta = -0.489 where pi< theta < 3 pi/2, find sin theta

Ayaana Buck 2021-09-09 Answered

Given that cosθ=0.489 where π<θ<3π2, find sinθ​​​​​​​

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Expert Answer

Obiajulu
Answered 2021-09-10 Author has 98 answers

Use the Pythagorean identity:

sin2θ+cos2θ=1

sin2θ=1cos2θ

Since θ is Quadrant III, then sinθ<0 so take the negative root:

sinθ=1cos2θ

sinθ=10.4892

sinθ0.872

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