Precalculus U2T1 - Define Trig Functions using Unit Circle

What is the radius of the unit circle?

• 0

• 1

• $\frac{1}{2}$

• $\frac{\sqrt{2}}{2}$
  

Based on the unit circle, how do we find the value of  $\sin\theta$  ?

• y

• x

•  $\frac{x}{y}$  

•  $\frac{y}{x}$  
  

Based on the unit circle, how do we find the value of $\cos\theta$ ? 

• y

• x

•  $\frac{x}{y}$  
  

•  $\frac{y}{x}$  
  

Based on the unit circle, how can we find the value of $\tan\theta$ ? 

•  $\frac{y}{r}$  
  

•  $\frac{x}{r}$  
  

•  $\frac{r}{y}$  
  

•  $\frac{y}{x}$  
  

How many degrees is ^π/₆ radians?

• 90°

• 60°

• 45°

• 30°

How many degrees is ^π/₄ radians?

• 30°

• 45°

• 60°

• 90°

How many degrees is ^π/₂ radians?

• 30°

• 45°

• 60°

• 90°

How many degrees is ^π/₃ radians?

• 30°

• 45°

• 60°

• 90°

What is a complete circle in radians?

• π

• 2π

• $\frac{\pi}{2}$

• 1

What is  $240\degree$  in radians?

•  $-\frac{\sqrt{2}}{2}$  

•  $\frac{4\pi}{3}$  

•  $\frac{3\pi}{4}$  

•  $-\frac{\sqrt{3}}{2}$