Secant of Three Right Angles
(Redirected from Secant of 270 Degrees)
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Theorem
- $\sec 270 \degrees = \sec \dfrac {3 \pi} 2$ is undefined
where $\sec$ denotes secant.
Proof
\(\ds \sec 270 \degrees\) | \(=\) | \(\ds \map \sec {360 \degrees - 90 \degrees}\) | ||||||||||||
\(\ds \) | \(=\) | \(\ds \sec 90 \degrees\) | Secant of Conjugate Angle |
But from Secant of Right Angle, $\sec 90 \degrees$ is undefined.
$\blacksquare$
Also see
- Sine of Three Right Angles
- Cosine of Three Right Angles
- Tangent of Three Right Angles
- Cotangent of Three Right Angles
- Cosecant of Three Right Angles
Sources
- 1968: Murray R. Spiegel: Mathematical Handbook of Formulas and Tables ... (previous) ... (next): $\S 5$: Trigonometric Functions: Exact Values for Trigonometric Functions of Various Angles