OpenStudy (anonymous):

does anyone know unit circle?

7 years ago
OpenStudy (shadowfiend):

I do. What do you need to know about it?

7 years ago
OpenStudy (anonymous):

what is the difference between a termanial point and a reference number?

7 years ago
OpenStudy (shadowfiend):

I believe a reference number is the smallest angle needed to get between any given point on the unit circle and the X axis. A terminal point, on the other hand, is an actual (x, y) coordinate point that exists on the unit circle. For example, take pi / 2, or 90 degrees. It has a reference angle of pi / 2, because the smallest angle between it and the x axis is 90 degrees (since it is exactly in the middle of the unit circle with respect to the x axis). The terminal point at pi / 2 is (0, 1) -- 0 on the x axis, 1 on the y axis.

7 years ago
OpenStudy (anonymous):

ohh okayy another thingg, the question asks to solve sin 1 on the figure and then a calculator, how do you calculate the value of it on the figure(meaning the unit circle?)

7 years ago
OpenStudy (shadowfiend):

As another example, take 3pi / 4, or 45 degrees. It has a reference number of pi / 4, because the shortest angle to get from 3pi / 4 to the X axis is the pi / 4 needed to get to pi / 2, which is directly on the X axis. Meantime, its terminal point is $$\left(\frac{\sqrt{2}}{2}, \frac{\sqrt{2}}{2}\right)$$.

7 years ago
OpenStudy (shadowfiend):

sin(1)?

7 years ago
OpenStudy (anonymous):

1 radian is a little less than 60 degrees or pi/3 radians. sin(pi/3) is .866, so sin(1) is close to that, but a little less.

7 years ago