Simplify Trig Expression F2623B
1. **State the problem:** Simplify the expression \( \frac{\cos(\theta)}{1 - \sin(\theta)} - \tan(\theta) \).
2. **Recall formulas and identities:**
- \( \tan(\theta) = \frac{\sin(\theta)}{\cos(\theta)} \)
- Important Pythagorean identity: \( \sin^2(\theta) + \cos^2(\theta) = 1 \)
3. **Rewrite the expression using the identity for \( \tan(\theta) \):**
$$ \frac{\cos(\theta)}{1 - \sin(\theta)} - \frac{\sin(\theta)}{\cos(\theta)} $$
4. **Find a common denominator to combine the terms:**
The common denominator is \( (1 - \sin(\theta)) \cos(\theta) \).
5. **Rewrite each term with the common denominator:**
$$ \frac{\cos^2(\theta)}{(1 - \sin(\theta)) \cos(\theta)} - \frac{\sin(\theta)(1 - \sin(\theta))}{(1 - \sin(\theta)) \cos(\theta)} $$
6. **Combine the numerators:**
$$ \frac{\cos^2(\theta) - \sin(\theta) + \sin^2(\theta)}{(1 - \sin(\theta)) \cos(\theta)} $$
7. **Use the Pythagorean identity \( \sin^2(\theta) + \cos^2(\theta) = 1 \) to simplify the numerator:**
$$ \frac{1 - \sin(\theta)}{(1 - \sin(\theta)) \cos(\theta)} $$
8. **Cancel the common factor \( 1 - \sin(\theta) \) in numerator and denominator:**
$$ \frac{1}{\cos(\theta)} $$
9. **Final simplified expression:**
$\sec(\theta)$
This means the original expression simplifies to the secant of \( \theta \).