Barrons AP Calculus - David Bock

interchange.

Less risky and more satisfying is to switch to parametric mode: Enter x = t^2 − 6t + 8 and y = t.

Then graph these equations in [−10,10] × [−10,10], for t in [−10,10], See Figure N1–12.

FIGURE N1–12

EXAMPLE 16

Let f (x) = x^3 + x; graph f −1(x).

SOLUTION: Recalling that f −1 interchanges x and y, we use parametric mode to graph

f: x = t, y = t^3 + t

and f −1: x = t^3 + t, y = t.

Figure N1–13 shows both f (x) and f −1(x).

FIGURE N1–13
Parametric equations give rise to vector functions, which will be discussed in connection with
motion along a curve in Chapter 4.

G. POLAR FUNCTIONS

Polar coordinates of the form (r, ) identify the location of a point by specifying , an angle of rotation
from the positive x-axis, and r, a distance from the origin, as shown in Figure N1–14.