Graph the unit circle using parametric equations with your calculator set to radian mode. Use a scale of . Trace the circle to find the sine and cosine of to the nearest ten-thousandth.
A)
B)
C)
D)

Question

Graph the unit circle using parametric equations with your calculator set to radian mode. Use a scale of  . Trace the circle to find the sine and cosine of   to the nearest ten-thousandth. ​
A)​ 
B)​ 
C)​ 
D)​

Quizplus · Accepted Answer

Using parametric equations, we have: 
$x = \cos(t)$ and $y = \sin(t)$, where $t$ goes from $0$ to $2\pi$.
When $t = \frac{3\pi}{2}$, we have:
$\cos(\frac{3\pi}{2}) = 0$
$\sin(\frac{3\pi}{2}) = -1$
Therefore, the point on the unit circle corresponding to $t=\frac{3\pi}{2}$ is at (0, -1).
Option B is the only point that lies on the unit circle and has y-coordinate -1, so the answer is B.

Graph the Unit Circle Using Parametric Equations with Your Calculator