### Home > CCA2 > Chapter Ch10 > Lesson 10.1.1 > Problem10-22

10-22.

For what values of $n$ does the equation $2x^2 + nx + 9 = 0$ have exactly one root?

This equation can be solved using the Quadratic Formula.
When does the Quadratic Formula yield exactly one solution/root?

The Quadratic Formula yields exactly one solution when the value inside the square root is zero.

$b^2 - 4ac = 0$ or in this case, $n^2 - 4(2)(9) = 0$.
Solve for $n$.