Please answer all questions and show work:

4) Find the vector 2u - v, given the vectors u and v below. 1I O O O 5) For unknown vectors a and b, it is They are orthogonal. given that a x b / 0. Which of the O They form an angle less than 90 degrees. O They are parallel. following must be true of a and b? O They form angle greater than 90 degrees. O None of the above 6) Find the approximate angle between the O 90 degrees vectors a = (-2, 3, 5) and b = (-4, 6, 10). O 180 degrees O 60 degrees O 0 degrees O None of the above