What are the exact values of cos((3pi)/4) radians and sin((3pi)/4) radians?

1 Answer
Jul 18, 2017

cos((3pi)/4)=-sqrt2/2

sin((3pi)/4)=sqrt2/2

Explanation:

cos((3pi)/4)=cos(pi-pi/4)=-cos(pi/4)=-sqrt2/2

sin((3pi)/4)=sin(pi-pi/4)=sin(pi/4)=sqrt2/2

Imagine the trigonometric circle in your mind.