# How do you use a calculator to evaluate tan^-1 3.9 in both radians and degree?

Mar 11, 2017

${75}^{\circ} 62$
$\frac{75.62 \pi}{180}$
$\frac{{265}^{\circ} 62 \pi}{180}$

#### Explanation:

Calculator and unit circle give:
tan x = 3.9 --> 2 solutions -->
$x = {75}^{\circ} 62$, and $x = 180 + 75.62 = {255}^{\circ} 62$
${180}^{\circ} - \to \pi$
${1}^{\circ} - - \to \frac{\pi}{180}$
$x = {75}^{\circ} 62 - - \to \frac{75.62 \left(\pi\right)}{180}$
$x = {255}^{\circ} 62 = \frac{255.62 \pi}{180}$