Graphing and Interpreting the Cosine Function

Find the coordinates of point P on the unit circle shown below.

• $\left(0.766,\ 0.642\right)$

• $\left(0.642,\ 0.766\right)$

• $\left(0.940,\ -0.342\right)$

• $\left(-0.342,\ 0.94\right)$

Find the coordinates of point Q on the unit circle shown below.

• $\left(0.766,\ 0.642\right)$

• $\left(0.642,\ 0.766\right)$

• $\left(0.940,\ -0.342\right)$

• $\left(-0.342,\ 0.940\right)$

Find ALL the angle values for when

 $\cos\theta=0.$  

•  $0\degree$  

•  $90\degree$  

•  $180\degree$  

•  $270\degree$  

•  $360\degree$  

An angle θ on the unit circle has a cosine of $\frac{3}{4}$  . What is the value of $\sin\theta$  ?

•  $\frac{2.646}{4}$  

•  $\frac{2.646}{3}$  

•  $\frac{3}{2.646}$  

•  $\frac{4}{2.646}$  

Consider angle $\theta$  in Quadrant II, where $\sin\theta=\frac{4}{5}$  . What is the value of  $\cos\theta$  ?

Consider angle $\theta$  in Quadrant III, where $\cos\theta=-\frac{1}{3}$  . What is the value of  $\sin\theta$  ?