Arcsec(x) Calculator — inverse secant function

How to use the arcsec(x) calculator
1. Enter a real number \(x\) such that \(|x| \ge 1\) and choose decimal places.
2. Press calculate arcsec(x). The answer is displayed in radians and degrees.
If x is outside the domain (\(-1 < x < 1\)), "NaN" is displayed.

Formulas used:
\[ \text{arcsec}(x) = \arccos\left(\frac{1}{x}\right) \quad \text{(principal value range: } [0,\pi/2) \cup (\pi/2,\pi] \text{)} \]
\[ \text{degrees} = \text{radians} \times \frac{180}{\pi} \]

• Domain: \( (-\infty, -1] \cup [1, \infty) \) (|x| ≥ 1)
• Range: \( [0 , \pi/2) \cup (\pi/2 , \pi] \) radians (\(0^\circ\) to \(180^\circ\), excluding 90°)