Problem Set 62: Parametric Equations

1. What is a system of parametric equations?

2. Some examples of a third parameter are time, length, speed, and scale. Explain when time is used as a parameter.

3. Explain how to eliminate a parameter given a set of parametric equations.

4. What is a benefit of writing a system of parametric equations as a Cartesian equation?

5. What is a benefit of using parametric equations?

6. Why are there many sets of parametric equations to represent on Cartesian function?

For the following exercises, eliminate the parameter t to rewrite the parametric equation as a Cartesian equation.

7. {x(t)=5ty(t)=82t

8. {x(t)=63ty(t)=10t

9. {x(t)=2t+1y(t)=3t

10. {x(t)=3t1y(t)=2t2

11. {x(t)=2ety(t)=15t

12. {x(t)=e2ty(t)=2et

13. {x(t)=4log(t)y(t)=3+2t

14. {x(t)=log(2t)y(t)=t1

15. {x(t)=t3ty(t)=2t

16. {x(t)=tt4y(t)=t+2

17. {x(t)=e2ty(t)=e6t

18. {x(t)=t5y(t)=t10

19. {x(t)=4costy(t)=5sint

20. {x(t)=3sinty(t)=6cost

21. {x(t)=2cos2ty(t)=sint

22. {x(t)=cost+4y(t)=2sin2t

23. {x(t)=t1y(t)=t2

24. {x(t)=ty(t)=t3+1

25. {x(t)=2t1y(t)=t32

For the following exercises, rewrite the parametric equation as a Cartesian equation by building an x-y table.

26. {x(t)=2t1y(t)=t+4

27. {x(t)=4ty(t)=3t+2

28. {x(t)=2t1y(t)=5t

29. {x(t)=4t1y(t)=4t+2

For the following exercises, parameterize (write parametric equations for) each Cartesian equation by setting x(t)=t or by setting y(t)=t.

30. y(x)=3x2+3

31. y(x)=2sinx+1

32. x(y)=3log(y)+y

33. x(y)=y+2y

For the following exercises, parameterize (write parametric equations for) each Cartesian equation by using x(t)=acost and y(t)=bsint. Identify the curve.

34. x24+y29=1

35. x216+y236=1

36. x2+y2=16

37. x2+y2=10

38. Parameterize the line from (3,0) to (2,5) so that the line is at (3,0) at t=0, and at (2,5) at t=1.

39. Parameterize the line from (1,0) to (3,2) so that the line is at (1,0) at t=0, and at (3,2) at t=1.

40. Parameterize the line from (1,5) to (2,3) so that the line is at (1,5) at t=0, and at (2,3) at t=1.

41. Parameterize the line from (4,1) to (6,2) so that the line is at (4,1) at t=0, and at (6,2) at t=1.

For the following exercises, use the table feature in the graphing calculator to determine whether the graphs intersect.

42. {x1(t)=3ty1(t)=2t1 and {x2(t)=t+3y2(t)=4t4

43. {x1(t)=t2y1(t)=2t1 and {x2(t)=t+6y2(t)=t+1

For the following exercises, use a graphing calculator to complete the table of values for each set of parametric equations.

44. {x1(t)=3t23t+7y1(t)=2t+3

t x y
–1
0
1

45. {x1(t)=t24y1(t)=2t21

t x y
1
2
3

46. {x1(t)=t4y1(t)=t3+4

t x y
-1
0
1
2

47. Find two different sets of parametric equations for y=(x+1)2.

48. Find two different sets of parametric equations for y=3x2.

49. Find two different sets of parametric equations for y=x24x+4.