Quiz #2

Quiz #2
September 8, 2015
MATH 251
This quiz is due by 4pm on Thursday, September 10, 2015.
You will be graded on both the correct answer and the correctness of the work that you provide to justify that
answer. I expect to see all of your work in a neat and orderly manner. If you want, you may work the problems
on other paper and turn in all your work.
1. Let a = h1, 2, 7i and b = h0, −4, 2i.
(a) Find b × a
(b) Find a unit vector that is orthogonal to the vectors a and b.
2. Find the equation of the plane that contains these lines.
r1 (t) = h1 + t, 1 − t, 2ti
r2 (s) = h2 − s, s, 2i