Reduce the equation to one of the standard forms, classify the surface, and sketch it.
33. y² = x² + 2²
34. 4x²y + 2z² = 0
35. x² + 2y 2z² = 0
36. y² = x² + 4z² + 4
37. x² + y² - 2x- 6y - z = 10 = 0
38. x² - y² - 2² - 4x2z + 3 = 0
39. x² - y² + 2² - 4x - 2z = 0