Question 924695
Parabola using only TWO given points?



{{{y=a(x-r)(x-s)}}}


Using s=-45
{{{y=a(x-r)(x-(-45))}}}
{{{y=a(x-r)(x+45)}}}


{{{highlight_green(a(x-r)=y/(x+45))}}}.............


Two points alone will not define a parabola.  You could allow a to be any value you want, as long as {{{highlight_green(a<>0)}}}; and then you can substitute for (-5,80) and solve for "r", the other root.