The polar equation is and
.
If the point has Cartesian coordinates
and polar coordinates
, then
and
.
Substitute in polar coordinates.
.
.
The slope of the tangent line is derivative of the function.
\Apply chain rule of derivatives : .
First find .
\
Consider .
Apply derivative on each side with respect to .
Apply product rule of derivatives: .
.
Find .
Consider .
Apply derivative on each side with respect to .
Apply product rule of derivatives: .
.
.
Substitute and
.
.
The slope of the tangent line of polar equation is
.
The curve equation is .
Substitute in polar coordinates.
.
.
Consider .
.
Consider .
.
.
Substitute and
.
.
The slope of the tangent line of polar equation is
.
The slope of the tangent line of polar equation is
.
The slope of the tangent line of polar equation is
.
The product of slopes is
\
.
The tangent lines of and
are perpendicular to each other.
Therefore, the curves and
are perpendicular. \ \
The curves and
are perpendicular.