## Trigonometry 7th Edition

$13.3^{\circ}$
$\cos\theta=0.9730$ can be rearranged as $\theta=\cos^{-1} 0.9730$. Ensuring that the calculator is in degrees, we type $\cos^{-1} 0.9730$ into the calculator and press enter: $\theta=\cos^{-1} 0.9730\approx13.3^{\circ}$.