Sum of Secant and Tangent
From ProofWiki
Theorem
- $\displaystyle \sec x + \tan x = \frac {1 + \sin x} {\cos x}$
Proof
| \(\displaystyle \) | \(\displaystyle \) | \(\displaystyle \) | \(\displaystyle \sec x + \tan x\) | \(=\) | \(\displaystyle \frac 1 {\cos x} + \frac {\sin x} {\cos x}\) | \(\displaystyle \) | \(\displaystyle \) | \(\displaystyle \) | by definition of tangent and secant | ||
| \(\displaystyle \) | \(\displaystyle \) | \(\displaystyle \) | \(\displaystyle \) | \(=\) | \(\displaystyle \frac {1 + \sin x} {\cos x}\) | \(\displaystyle \) | \(\displaystyle \) | \(\displaystyle \) |
$\blacksquare$