Question 250565
Indicate the axis of symmetry of the parabola
y = x^2 + 8x + 20
.
Remember the quadratic formula?
{{{(-b +- sqrt(b^2-4ac))/(2a)}}}
.
Well, the axis of symmetry can be found by:
{{{x = -b/(2a)}}}
The quadratic formula but without the +- radical.
.
{{{x = -b/(2a)}}}
{{{x = -8/(2(1))}}}
{{{x = -8/2}}}
{{{x = -4}}}  (axis of symmetry)