The equation of conic is
.

The general form of a conic is
.
Here
,
,
,
,
and
.
Find
.

The conic is an ellipse.
\The angle is
.
Substitute
,
and
in the above equation.

Assume that the angle lies on second quadrant.
\
Observe the diagram :
\
.
Find
and
.
Half angle identity :
.

Half angle identity :
.

.
Find equations for
and
.
.
Substitute
and
in the above equation.
.
.
Substitute
and
in the above equation.
.
Substitute
and
in equation (1).



The standard form of equation is
.