Which of the following is the equation of a sphere with radius r = 4 centered at the point (0, -1, 2)? Select one: O None of them. O x2 + ( y + 1)2 + (2 - 2)2 = 16 O x2 + (y + 1)2 + ( 2 + 2)2 = 16 O (x + 1)2 + (y + 2)2 + 22 = 16 O (x - 1)2 + (y + 2)2+ 22 = 16If a = (1,1,2) and b = (3,1,6), then which of the following gives lb 3a| ? Select one: 0 (0,4,0) 0 None of them. Ox/ Ifa=2i+6j -3k and b = -i - 3j + k then which of the following vectors is a unit vector in the direction of 2b + a? Select one: O k 0 k 0 2k 0 -2k 0 None of them Which of the following point is the projection of the point (0, 4, 2) on the yzplane? Select one: Q (4, 2, 0) O (0, 4, 0) Q (0, 4, 2) 0 None of them. 0 (0, 2, 0)