# What is the inverse cosine of 1/3?

##### 1 Answer

Nov 29, 2015

#### Explanation:

Since

#costheta=1/3#

#theta=cos^-1(1/3)#

#theta~~70.53^@#

However, since cosine is also positive in quadrant

#theta=360^@-70.53^@#

#theta~~289.47^@#