The curve equations are and
.
Graph:
\Graph the curves and
:
Observe the graph:
\The curve crosses itself at the point .
The curve crosses itself at the point .
and
and
.
if , then
.
if , the
is never zero.
Therefore, is not a valid solution.
.
Apply pythagorean identity : .
.
Apply double angle identity: .
.
The slope of the tangent line is .
.
Consider .
Apply derivative on each side with respect to .
.
Consider .
Apply derivative on each side with respect to .
.
Substitute and
in
.
.
The slope of the tangent line is at the point.
Substitute ,
and
.
.
The slope intercept form is .
Substitute and
.
.
The tangent line equations are .
The tangent line equations are .