# Secant of 60 Degrees

## Theorem

$\sec 60 \degrees = \sec \dfrac \pi 3 = 2$

where $\sec$ denotes secant.

## Proof

 $\displaystyle \sec 60 \degrees$ $=$ $\displaystyle \frac 1 {\cos 60 \degrees}$ Secant is Reciprocal of Cosine $\displaystyle$ $=$ $\displaystyle \frac 1 {\frac 1 2}$ Cosine of $60 \degrees$ $\displaystyle$ $=$ $\displaystyle 2$ multiplying top and bottom by $2$

$\blacksquare$