What are the roots of this equation x^2-4x+9=0?

Roots is a fancy word for zero, which is also another fancy word for the x intercept.

You can factor a quad or use the quadratic equation to get zeros.

In this case, its non-factorable. So you gotta use the quadratic.

Using the quadratic equation you get : x = -2 ± √-1 (√5),

which can be rewritten as x = -2 ± i(√5)

Function was : x^2 + 4x + 9

For quad, I identified the following:

A = 1

B = 4

C = 9

I also added a picture of the formula in the attached.