The expression in the image you uploaded is:

$\frac{\sec\theta}{\sqrt{\sec^2\theta - 1}}$

To simplify this, we can use a trigonometric identity:

$\sec^2\theta - 1 = \tan^2\theta$

Thus, the expression becomes:

$\frac{\sec\theta}{\sqrt{\tan^2\theta}} = \frac{\sec\theta}{|\tan\theta|}$

Therefore, the simplified form of the expression is:

$\frac{\sec\theta}{|\tan\theta|}$

Would you like to explore further, or ask for details on how this simplification works?

Here are some related questions for practice:

1. What is the relationship between $\sec\theta$ and $\cos\theta$?
2. How can you express $\tan\theta$ in terms of $\sin\theta$ and $\cos\theta$?
3. Can you apply this identity $\sec^2\theta - 1 = \tan^2\theta$ in other trigonometric expressions?
4. What happens if $\theta = 0$? Is the expression valid?
5. How can you graph the original expression and its simplified form?

Tip: Understanding trigonometric identities can make simplifying expressions much easier. Familiarize yourself with the key ones!