# How to find the value of x where 0<=x<=360^@ for sec x= -1.7172?

$\sec x = \frac{1}{\cos} x = - 1.7172$
$\cos x = \frac{1}{- 1.7172} = - 0.58$
Calculator and trig unit circle give: $x = \pm 125.45 \mathrm{de} g$