Question

For the equation for sin(x/2), there's a +/- sign in front; does the sign depend on x or on x/2?

Answer 1

for example if x was in the third quadrant, it would be negative for sign, but if if x/2 was in the second quadrant, it would be positive - so which do you look at?

Answer 2

Are you talking about the half angle formula?

Answer 3

yep

Answer 4

It might be good to just try \(\pi/2\) and \(\pi/4\) as test points.

Answer 5

as in, sin(π/2) and sin(π/4)?

Answer 6

Yeah