Question 1187756
<pre>
{{{matrix(5,3,

(x-h)^2,""="",-4a(y-k),
"","","",
(0-h)^2,""="",-4a(0-k),
(1-h)^2,""="",-4a(0-k),
(5-h)^2,""="",-4a(-20-k))}}}

{{{system(matrix(3,3,
h^2,""="",4ak,
(1-h)^2,""="",4ak,
(5-h)^2,""="",80a+4ak))}}}

{{{h^2}}}{{{""=""}}}{{{(1-h)^2}}}  <--since both equal 4ak

{{{h^2}}}{{{""=""}}}{{{1-2h+h^2}}} <--subtract h<sup>2</sup> from both sides

{{{0}}}{{{""=""}}}{{{1-2h}}}

{{{2h}}}{{{""=""}}}{{{1}}}

{{{h}}}{{{""=""}}}{{{1/2}}}   

{{{h^2}}}{{{""=""}}}{{{1/4}}}

{{{4ak}}}{{{""=""}}}{{{1/4}}}  <--since h<sup>2</sup> equals 4ak

{{{(5-h)^2}}}{{{""=""}}}{{{80a+4ak}}}

{{{(5-1/2)^2}}}{{{""=""}}}{{{80a+1/4}}}

{{{(4&1/2)^2}}}{{{""=""}}}{{{80a+1/4}}}

{{{(9/2)^2}}}{{{""=""}}}{{{80a+1/4}}}  

{{{81/4}}}{{{""=""}}}{{{80a+1/4}}}  <--multiply through by 4

{{{81}}}{{{""=""}}}{{{320a+1}}}

{{{80}}}{{{""=""}}}{{{320a}}}

{{{80/320}}}{{{""=""}}}{{{a}}}

{{{1/4}}}{{{""=""}}}{{{a}}}

{{{4ak}}}{{{""=""}}}{{{1/4}}}

{{{4(1/4)k}}}{{{""=""}}}{{{1/4}}}

{{{k}}}{{{""=""}}}{{{1/4}}}

So the equation of the parabola is

{{{(x-h)^2}}}{{{""=""}}}{{{-4a(y-k)}}}

{{{(x-1/2)^2}}}{{{""=""}}}{{{-4(1/4)(y-1/4))}}}

You simply further.

Edwin</pre>