Chapter 4 Quadratic Functions and Factoring - 4.8 Use the Quadratic Formula and the Discriminant - 4.8 Exercises - Skill Practice - Page 297: 65

$2x^2+4x+4$

We can write a quadratic function as: $f(x)=k(x-(-1+i))(x-(-1-i))$ Thus, we obtain: $k[x(x-(-1+i))-(-1+i)(x-(-1-i))]$ $k[x(x+1-i-(-1+i)(x+1+i)]$ $k(x^2+2x+2)$ $kx^2+2kx+2k$ It is given that $c=4$ so $c=2k=4 \rightarrow k=2$ Hence: $2x^2+4x+4$