Use a calculator to find the value of the expression in radian measure rounded to two decimal places.
-$\sec ^ { - 1 } \left( - \frac { 5 } { 4 } \right)$
A) $143.13$
B) $- 0.93$
C) $2.50$
D) $- 53.13$

Question

Quizplus · Accepted Answer

The secant inverse function, $\sec^{-1}(x)$, gives the angle whose secant is $x$. Since $\sec(\theta) = \frac{1}{\cos(\theta)}$, $\sec^{-1}(-\frac{5}{4})$ corresponds to finding an angle $\theta$ such that $\cos(\theta) = -\frac{4}{5}$. In radian measure, this angle is approximately $2.50$ radians.

Use a Calculator to Find the Value of the Expression sec⁡−1(−54)\sec ^ { - 1 } \left( - \frac { 5 } { 4 } \right)sec−1(−45​)

Use a Calculator to Find the Value of the Expression $\sec ^ { - 1 } \left( - \frac { 5 } { 4 } \right)$