# How do you evaluate sec(tan^-1(8)) without a calculator?

$\sqrt{65}$
${\tan}^{-} 1 \left(8\right)$ means the angle whose tan is 8
Mark in $\theta$ opposite the side length 8.
The hypotenuse is length $\sqrt{65}$ -Pythagoras
The sec of $\theta$ is hypotenuse divided by adjacent