Question

What is sin 7pi/4? I'm currently taking a tirg course and need help

Answer 1

To ease the understanding, let's write it in degrees and not in Radian:

Formula of conversion: Degree°/180 = Radian/π

Convert 7π/4 in degrees: = (7x180)/4 = 315°

This angle is in the IV th Quadrant of the UNIT circle. So you can write 315° or - 45° .

sin(7π/4) = sin(315°) = sin( - 45°) = - sin(45°) = - (√2)/2