Defining and understanding trigonometric ratios

 $\tan\left(\frac{4\pi}{3}\right)=$  

•  $\frac{\sqrt{3}}{3}$  

•  $\sqrt{3}$  

•  $\frac{\sqrt{3}}{2}$  

•  $-\sqrt{3}$  

Answer explanation

Cosine deals with the x-coordinate.

Sine deals with the y-coordinate.

Tangent deals with y/x.

 $\cos\left(\frac{5\pi}{4}\right)=?$  

•  $-\frac{\sqrt{3}}{2}$  

•  $\frac{\sqrt{3}}{2}$  

•  $-\frac{\sqrt{2}}{2}$  

•  $\frac{\sqrt{2}}{2}$  

• undefined

cos 150^o

• -1/2

• 1/2

• √3/2

• -√3/2

• 17/8

• -15/17

• -17/15

• -15/8

• -8/15

What is the exact value of $\csc\left(\frac{2\pi}{3}\right)$  ?

•  $\frac{\sqrt{3}}{2}$  

•  $\frac{2\sqrt{3}}{3}$  

•  $-\frac{1}{2}$  

•  $-2$  

Given the ordered pair (-¹/₂ , ^√3/₂), what is the value of cosine?

• √3

• ^-1/₂

• ^√3/₂

• ^√3/₃

Evaluate tan(30°), without the use of a calculator.

• $\frac{\sqrt{3}}{2}$

• $\frac{\sqrt{1}}{2}\ or\ \frac{1}{2}$

• $\frac{1}{\sqrt{3}}\ or\ \frac{\sqrt{3}}{3}$

• $\frac{2}{\sqrt{3}}\ or\ \frac{2\sqrt{3}}{3}$