What are the sine, cosine, and tangent of θ=3π4 radians?

1 Answer
May 15, 2018

sin(3π4)=22

cos(3π4)=22

tan(3π4)=22

Explanation:

first, you need to find the reference angle and then use the unit circle.

θ=3π4

now to find the reference angle you have to determine that angle is in which quadrant

3π4 is in the second quadrant because it is less than π

which it is 4π4=180

second quadrant means its reference angel = π3π4=π4
then you can use the unit circle to find the exact values or you can use your hand!!

now we know that our angle is in the second quadrant and in the second quadrant just sine and cosecant are positive the rest are negative


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so

sin(3π4)=sin(π4)=22

cos(3π4)=cos(π4)=22

tan(3π4)=tan(π4)=22