-√(16y^2) if y<0

Question

`-√(16y^2)` if y<0

Answer 1

4y

Explanation:

You want the simplified form of -√(16y²) if y < 0.

Simplified radical

The square root function returns the positive root, so this is ...

`-√(16y^2)=-4|y|`

The absolute value changes the sign of its negative arguments, so this is ...

`-4|y| = -4(-y) = \boxed{4y}\qquad\text{for $y < 0$}`