Question 983058
Start with vertex form,
{{{y=a(x-4)^2-5}}}
Use the point.
{{{-1=a(0-4)^2-5}}}
{{{-1=a(16)-5}}}
{{{a(16)=4}}}
{{{a=4/16}}}
{{{a=1/4}}}
{{{y=(1/4)(x-4)^2-5}}}
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*[illustration fd4.JPG].