Question 303150
{{{f(x)=2x^2+12x+9}}}
Complete the square to put the equation into vertex form.
{{{g(x)=a(x-h)^2+k}}} where the vertex is ({{{h}}},{{{k}}}) 
The vertex lies on the axis of symmtery.
{{{f(x)=2(x^2+6x)+9}}}
{{{f(x)=2(x^2+6x+9)+9-18}}}
{{{f(x)=2(x+3)^2-9}}}
The axis of symmetry is {{{x=-3}}}.
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{{{ drawing( 300, 300, -5, 5, -10, 5,grid(1),circle(-3,-9,.2),green(line(-3,-20,-3,20)), graph( 300, 300, -5, 5, -10, 5, 2x^2+12x+9) )}}}