Question 883004
A parabola equation in standard form using that vertex would be {{{y=a(x+3)^2+5}}} and solving for a will give a formula to let you find the value for a using the point given on the parabola.


{{{a(x+3)^2=y-5}}}
{{{a=(y-5)/(x+3)^2}}}
{{{a=(-1-5)/(-6+3)^2}}}, substituting the point (-6,-1)
{{{a=-6/(-3)^2}}}
{{{a=-6/9}}}
{{{a=-2/3}}}


The equation (or function) can be {{{highlight(y=-(2/3)(x+3)^2+5)}}}.