Question

The point (a, b) is the point on the unit circle...

Answer 1

Find an angle...

Answer 2

so, on the unit circle, let's take the angle pi, What are its coordinates?

Answer 3

Then, what is the sin(pi) and cos(pi)

Answer 4

isn't pi 180 degrees?

Answer 5

also isn't sin(pi) = 0 and cos(pi) = -1?

Answer 6

yep, 180 deg. and sin is 0 and cos is -1. Now what were the coordinates for that on the unit circle?

Answer 7

180 degrees = (-1,0) and 270 degrees = (0,-1)?

Answer 8

Why did you tell me 3pi/2? But anyways, so what do you notice about pi's coordinates when you compare it to the sine and cosine?

Answer 9

well sin is positive and cosine negative?

Answer 10

the sine and cosine were 0 and -1 respectively. yes? What are the coordinates on the unit circle for pi?

Answer 11

(-1,0)

Answer 12

ahh there we go, now, what else was -1 and 0?

Answer 13

looking at my chart here I do not see another (-1, 0) I see a (1,0)