Tan Identity Ad1Eba
1. The problem asks to find the expression equivalent to $1 + \tan^2(A)$.
2. We use the Pythagorean identity in trigonometry:
$$1 + \tan^2(A) = \sec^2(A)$$
3. This identity comes from the fundamental Pythagorean identity:
$$\sin^2(A) + \cos^2(A) = 1$$
Dividing both sides by $\cos^2(A)$ gives:
$$\frac{\sin^2(A)}{\cos^2(A)} + \frac{\cos^2(A)}{\cos^2(A)} = \frac{1}{\cos^2(A)}$$
Simplifying:
$$\tan^2(A) + 1 = \sec^2(A)$$
4. Therefore, the correct answer is $\sec^2(A)$.