Simplifying a negative square root is exactly the same as simplifying a positive square root. We add the imaginary unit i to the front the square root to indicate that it is an imaginary answer.
Solving Quadratic Equations with Negative Square Roots
Isolate the squared variable.
Take the square root. If the square root is negative, indicate the solution is imaginary by using the imaginary unit i.
Completing the Square with Negative Square Roots
Follow the completing the square steps in lesson 2.4. If the square root is negative, indicate the solution is imaginary by using the imaginary unit i.