Question 810518
y=x^2+4x+3
x coordinate of the vertex is given by -b/2a = -4/2*1 = -2
now substitute for x in the equation
y = (-2)^2 +4*(-2) + 3
y = -1
vertex is (-2, -1)
here is the graph
{{{ graph( 300, 200, -5, 5, -10, 10, x^2 +4x +3) }}}