If you want to sketch a curve expressed in polar form
there are some elementary things to remember.
-
cannot be negative! If some value of
gives a negative value for
the curve is not defined there. - is the angle the radius vector makes with the positive
– axis in a clockwise sense. -
If
is a function ofthen the curve will have
petals, because asincreases from 0 to
equivalent to one rotation about the origin,
increases from 0 to
giving rise to one petal for each increases of
by
-
The maximum value of
is often when
or
is 1, 0 or -1.
The graph
-is a maximum when
The curve has 4 petals.
The cardioid
– when
is max and when
When 
