Question

Write a quadratic function f whose only zero is -9

Answer 1

Answer:

x² + 18x + 81 = 0

Step-by-step explanation:

For the zero to -9, the equation has to be x + 9.

x = -9

x + 9 = 0

Since the only zero is -9, square the equation.  Expand to get the function

(x + 9)² = 0

x² + 18x + 81 = 0

Answer 2

Answer:

$x^{2}+18x+81=0$

Step-by-step explanation:

For it to have zero of -9 it is (x+9)^2. Expand that out and you get the answer.