# How do you calculate  (cos^-1) ((sqrt10)/7)?

Oct 5, 2015

$\approx 63.14372854$

#### Explanation:

What you're looking for is the angle whose cosine is $\frac{\sqrt{10}}{7}$.

So you need to find out what $\theta$ is in $\cos \theta = \frac{\sqrt{10}}{7}$.

You will need to use a calculator for this. Look for a button saying ${\cos}^{-} 1$. Select that, then type in $\frac{\sqrt{10}}{7}$.

You will get 63.14372854...