Observe the graph :
\Focus is
.
Equation of tangent line is .
Since the point on the graph lie on -axis,
.
Substitute in
.
The point is at and
is at
.
Find lengths of the legs of the isosceles triangle.
\The lengths of the legs of the isosceles triangle are .
Since the lenghth of the isosceles traingle are , the distance from
to the point of tangency
is
.
Find the tangent line distance.
\Substitute ,
and
.
Substitute in above equation.
and
.
At , the value of
is
.
Find the the value of at
.
Substitute in
.
At , the value of
is
.
The point of tangency line is located at .
The equation of parabola is .
Focus is
.
Substitute ,
and
in
.
and
.
The parabola lie on above - axis, so
is positive.
Thus, the value of is
.
Find the equation of a parabola.
\Substitute ,
and
in
.
The parabola equation is .
The parabola equation is .