http://www.ck12.org Chapter 10. Polar and Parametric Equations
Notice how when these partial graphs are examined there is no intersection at anything besidest=±2 and the points
(2, 2) and (-2, -2) While the paths of the graphs intersect in four places, they intersect at the same time only twice.
- First check to see if the point (-2, 6) produces a matching time for the original function.
TABLE10.3:
− 2 =t^2 − 10
8 =t^2
± 2
√
2 =t
6 = 2 t− 4
20 =t
The point does not live on the original function. Now, you must check to see if it lives on the inverse.
TABLE10.4:
6 =t^2 − 10
± 4 =t
− 2 =t 2 − 6
4 = 2 t
8 =t
The point does not live on the inverse either.
3.x 1 = 4 t;y 1 =t^2 −16 The inverse is:
x 2 =t^2 − 16
y 2 = 4 t
Solve fortwhenx 1 =x 2 andy 1 =y 2.
4 t=t^2 − 16
0 =t^2 − 4 t− 16
t=^4 ±
√ 16 − 4 · 1 ·(− 16 )
2 =
4 ± 4
√
5
2 =^2 ±^2
√
5
The points that correspond to these two times are: