Given that cos t=(3/4) and that P(t) is a point in the fourth quadrant, what is sin (t)?

1 Answer
Apr 5, 2018

sin(θ)=74

Explanation:

Start with the identity:

sin(θ)=±1cos2(θ)

We are told that θ is in the fourth quadrant and we know that the sine function is negative in the fourth quadrant, therefore, we shall choose the negative case of the identity:

sin(θ)=1cos2(θ)

Substitute cos2(θ)=(34)2:

sin(θ)=1(34)2

sin(θ)=1616916

sin(θ)=716

sin(θ)=74