The expression in the image is asking to simplify $\sqrt{-10}$.

This involves a negative number under the square root, which is not a real number. In mathematics, the square root of a negative number introduces imaginary numbers.

To simplify:

$\sqrt{-10} = \sqrt{-1} \times \sqrt{10} = i\sqrt{10}$

Where $i$ is the imaginary unit, defined as $i = \sqrt{-1}$.

Thus, the simplified form is $i\sqrt{10}$.

Would you like further details or have any questions?

Here are five related questions for further exploration:

1. How do you simplify the square root of other negative numbers?
2. What is the significance of the imaginary unit $i$ in complex numbers?
3. How do you add or subtract imaginary numbers?
4. How can we represent complex numbers in the polar form?
5. How do complex numbers appear in real-world applications?

Tip: Whenever you see a negative number inside a square root, think of using imaginary numbers, since real square roots only apply to non-negative numbers.