Question

find the zeros of the function f(x) = x^2+6x+18

Answer 1

\[f(x)=x^2+6x+18\]

\[x^2+6x+18=0\]
\[\Delta=b^2-4*a*c\]
\[\Delta=6^2-4*1*18\]
\[\Delta=-36\]
than we have to change the domain
\[\mathbb{R}\to\mathbb{C}\]
\[i^2=-1\]
therefore\[-36=36i^2\]
\[x=\frac{-b\pm\sqrt{\Delta}}{2a}\]
\[x=\frac{-6\pm\sqrt{36i^2}}{2}\]
\[x=\frac{-6\pm6i}{2}\]
\[x=-3\pm3i\]
\[\boxed{\boxed{x_1=-3+3i~~and~~x_2=-3-3i}}\]

Answer 2

Thank you very much!

Answer 3

nop