The curve equations are
and
.
Two curves are said to be orthogonal trajectories when the slopes of the tangent line to both the curves is equal to
.
Slope of the tangent is derivative of the curve.
\Consider
.
.
The curve equation is
.
Apply derivative on each side with respect to
.

Substitute
in above expression.
.
Slope of the tangent to the curve
is
.
Consider
.
Apply derivative on each side with respect to
.

Slope of the tangent to the curve
is
.
Determine
:
.
Therefore both the curves are orthogonal to each side.
\Graph both the curves.
\Consider different values of
and
.
Graph each curve for different values of
and
.

Clearly the graph of the two curves are orthogonal to each side.
\The two curves
and
are orthogonal to each other.