Problem Set 59: Polar Coordinates

1. How are polar coordinates different from rectangular coordinates?

2. How are the polar axes different from the x– and y-axes of the Cartesian plane?

3. Explain how polar coordinates are graphed.

4. How are the points (3,π2) and (3,π2) related?

5. Explain why the points (3,π2) and (3,π2) are the same.

For the following exercises, convert the given polar coordinates to Cartesian coordinates with r>0 and 0θ2π. Remember to consider the quadrant in which the given point is located when determining θ for the point.

6. (7,7π6)

7. (5,π)

8. (6,π4)

9. (3,π6)

10. (4,7π4)

For the following exercises, convert the given Cartesian coordinates to polar coordinates with r>0,0θ<2π. Remember to consider the quadrant in which the given point is located. 11. (4,2) 12. (4,6) 13. (3,5) 14. (10,13) 15. (8,8) For the following exercises, convert the given Cartesian equation to a polar equation. 16. x=3 17. y=4 18. y=4x2 19. y=2x4 20. x2+y2=4y 21. x2+y2=3x 22. x2y2=x 23. x2y2=3y 24. x2+y2=9 25. x2=9y 26. y2=9x 27. 9xy=1 For the following exercises, convert the given polar equation to a Cartesian equation. Write in the standard form of a conic if possible, and identify the conic section represented. 28. r=3sinθ 29. r=4cosθ 30. r=4sinθ+7cosθ 31. r=6cosθ+3sinθ 32. r=2secθ 33. r=3cscθ 34. r=rcosθ+2 35. r2=4secθcscθ 36. r=4 37. r2=4 38. r=14cosθ3sinθ 39. r=3cosθ5sinθ For the following exercises, find the polar coordinates of the point. 40. Polar coordinate system with a point located on the third concentric circle and pi/2.

41.
Polar coordinate system with a point located on the third concentric circle and midway between pi/2 and pi in the second quadrant.

42.
Polar coordinate system with a point located midway between the first and second concentric circles and a third of the way between pi and 3pi/2 (closer to pi).

43.
Polar coordinate system with a point located on the fifth concentric circle and pi.

44.
Polar coordinate system with a point located on the fourth concentric circle and a third of the way between 3pi/2 and 2pi (closer to 3pi/2).

For the following exercises, plot the points.

45. (2,π3)

46. (1,π2)

47. (3.5,7π4)

48. (4,π3)

49. (5,π2)

50. (4,5π4)

51. (3,5π6)

52. (1.5,7π6)

53. (2,π4)

54. (1,3π2)

For the following exercises, convert the equation from rectangular to polar form and graph on the polar axis.

55. 5xy=6

56. 2x+7y=3

57. x2+(y1)2=1

58. (x+2)2+(y+3)2=13

59. x=2

60. x2+y2=5y

61. x2+y2=3x

For the following exercises, convert the equation from polar to rectangular form and graph on the rectangular plane.

62. r=6

63. r=4

64. θ=2π3

65. θ=π4

66. r=secθ

67. r=10sinθ

68. r=3cosθ

69. Use a graphing calculator to find the rectangular coordinates of (2,π5). Round to the nearest thousandth.

70. Use a graphing calculator to find the rectangular coordinates of (3,3π7). Round to the nearest thousandth.

71. Use a graphing calculator to find the polar coordinates of (7,8) in degrees. Round to the nearest thousandth.

72. Use a graphing calculator to find the polar coordinates of (3,4) in degrees. Round to the nearest hundredth.

73. Use a graphing calculator to find the polar coordinates of (2,0) in radians. Round to the nearest hundredth.

74. Describe the graph of r=asecθ;a>0.

75. Describe the graph of r=asecθ;a<0. 76. Describe the graph of r=acscθ;a>0.

77. Describe the graph of r=acscθ;a<0. 78. What polar equations will give an oblique line? For the following exercises, graph the polar inequality. 79. r<4 80. 0θπ4 81. θ=π4,r2 82. θ=π4,r3 83. 0θπ3,r<2 84. [latex]\frac{-\pi }{6}<\theta \le \frac{\pi }{3},-3