Question

Why is sin -pi/2 equal to zero and not 1/2?

Answer 1

oops!

Answer 2

at -pi/2, y = -1,
sin(-pi/2) = -1/r = -1, and r = 1

Answer 3

so, sin(-pi/2) = -1 instead

Answer 4

Remember that sin(angle) represents the vertical component of a line drawn at (angle). if you look at the above picture, you can see that -pi/2 radians is straight down. In other words, its vertical component is -1. therefore, sin(-pi/2) = -1

Answer 5

Thank you!