Question

Kathy describes a quadratic function to one of her classmates by saying, “the lead coefficient of this function is 1, the sum of this functions roots is −4, and the product of its roots is 4.” Which function could be the one Kathy is describing?
A- f(x) = x2 – 4x – 4
B- f(x) = x2 + 4x – 4
C- f(x) = x2 + 4x + 4
C- f(x) = x2 – 4x + 4

Answer 1

Answer:

C - f ( x ) = x²+ 4x + 4

Step-by-step explanation:

Let the roots be α and β.

Sum of the roots is - 4,

α + β = - 4

Product of the roots is 4,

αβ = 4

x² - ( α + β )x + αβ

= x² - ( - 4 )x + 4

= x² + 4x + 4