Simplify Trig Expression 3Ad9B9
1. **State the problem:** Simplify the expression $$\frac{\cos(\theta)}{1 - \sin(\theta)} - \tan(\theta)$$.
2. **Recall formulas and identities:**
- $$\tan(\theta) = \frac{\sin(\theta)}{\cos(\theta)}$$
- Pythagorean identity: $$\sin^2(\theta) + \cos^2(\theta) = 1$$
3. **Rewrite the expression:**
$$\frac{\cos(\theta)}{1 - \sin(\theta)} - \frac{\sin(\theta)}{\cos(\theta)}$$
4. **Find a common denominator:**
The common denominator is $$\cos(\theta)(1 - \sin(\theta))$$.
5. **Rewrite each term with the common denominator:**
$$\frac{\cos^2(\theta)}{\cos(\theta)(1 - \sin(\theta))} - \frac{\sin(\theta)(1 - \sin(\theta))}{\cos(\theta)(1 - \sin(\theta))}$$
6. **Combine the fractions:**
$$\frac{\cos^2(\theta) - \sin(\theta)(1 - \sin(\theta))}{\cos(\theta)(1 - \sin(\theta))}$$
7. **Expand the numerator:**
$$\cos^2(\theta) - \sin(\theta) + \sin^2(\theta)$$
8. **Use the Pythagorean identity:**
Since $$\cos^2(\theta) + \sin^2(\theta) = 1$$, numerator becomes:
$$1 - \sin(\theta)$$
9. **Simplify the fraction:**
$$\frac{1 - \sin(\theta)}{\cos(\theta)(1 - \sin(\theta))}$$
10. **Cancel common factors:**
$$1 - \sin(\theta)$$ cancels out, leaving:
$$\frac{1}{\cos(\theta)}$$
11. **Final answer:**
$$\boxed{\sec(\theta)}$$
This means the original expression simplifies to $$\sec(\theta)$$, which is the reciprocal of cosine.