# How do you write the equation cosalpha=0.5 in the form of an inverse function?

Feb 28, 2018

We need to solve for $\alpha$

$\cos \alpha = 0.5$

we need to "undo" $\cos$. To do that,w e apply it's inverse, $a r c c o s$ or ${\cos}^{-} 1$

${\cos}^{-} 1 \left(\cos \alpha\right) = {\cos}^{-} 1 \left(0.5\right)$

$\alpha = {\cos}^{-} 1 \left(0.5\right)$

We can solve this, which gives us that $\alpha = \frac{\pi}{3}$ or $5 \frac{\pi}{3}$