Texts: #18 help please
Skill Building In Problems 9-12 find the center and radius of each circle. Write the standard form of the equation.
9. (4,2), r = 12
10. (0,12), r = 1
11. (0,121), r = 7
In Problems 13-22 write the standard form of the equation and the general form of the equation of each circle of radius r and center (h,k). Graph each circle.
13. r = 2, A = 0.014
14. r = 3, A = 0.015
15. r^2 + h^2 - k = 0.216
16. r = 3h - k - 1.0
17. r^4 + h^4 - k^2 = 2
18. r^4 + h^4 - k^2 = -2, h = 7, k = -5
19. -2a - 2n - k - a = 0
20. In Problems 23-30:
a) find the center (h,k) and radius r of each circle
b) graph each circle
c) find the intercepts if any
23. r = 4
24. x + y - 1 = 1
25. 2x - 3 + 2y = 8
26. 3x + 1 + 3y - 1 = 6
27. x + y - 2x - 4y - 4 = 0
28. x + y + 4r + 2y - 20 = 0
29. x + y + 4x - 4y - 10 = 0
30. x + y - 6r + 2y + 9 = 0
31. 3x + y - x + 2y = 1
32. 2x + 2y^2 - 12x + 8y = 24
33. 2x + 2y + 8r + 7 = 0
34. 2 + 8r + 2y = 0
35. 3x + 3y - 12y = 0
In Problems 37-44, find the standard form of the equation of each circle.
37. Center at the origin and containing the point (-2,3)
38. Center (1,1) and containing the point (-3,2)