Barrons AP Calculus

Figure  N1–15

A polar function may also be expressed parametrically:

x   =   r   cos θ, y    =   r   sin θ

In this form, the curve r = 2 + 4 sin θ from Example 17 would be defined by:

x(θ)    =   (2  +   4   sin θ)  cos θ, y(θ) =   (2  +   4   sin θ)  sin θ

BC  ONLY

Example 18 __

Find the (x,y) coordinates of the point on r = 1 + cos θ where .

SOLUTION: At .

Since and , the point is

.