Question 940628
{{{f(x)=x^2+2x-3}}}

First write it in vertex form: complete square
{{{f(x)=(x^2+2x+_)-_-3}}}
{{{f(x)=(x^2+2x+1)-1-3}}}
{{{f(x)=(x+1)^2-4}}}

The vertex is ({{{-1}}},{{{-4}}})  => minimum (parabola opens up)

The axis of sym. is {{{x=-1}}}
Y-int: {{{-4}}}
D:  (R}}} all real numbers
R: { {{{y}}} element {{{R}}} : {{{y>=-4}}} }


{{{drawing( 600,600, -10, 10, -10, 10,locate(-1.4,-4,V(-1,-4)),circle(-1,-4,.13),green(line(-1,10,-1,-10)), graph( 600,600, -10, 10, -10, 10, x^2+2x-3)) }}}