Fall 2014 – MATH 151, Sections 549-551
Quiz #2
DIRECTIONS. Read each problem carefully and work it out in the space provided. Put a box around
the answer you believe best answers the question. Calculators are not allowed.
Problem 1. Find the cosine of the angle between the two vectors h2, 5i and h−1, 3i.
(a)
√17
29
√
(b)
(c)
3
2
√13
290
(d) None of the above.
Problem 2. Let m = h1, 2i and n = h4, 3i. Find the vector projection of m onto n.
(a) h 85 , 65 i
(b) h8, 6i
40 √
(c) h √
, 305 i
5
(d) None of the above.
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Math 151 Fall 2014
Quiz #2
2
Problem 3. Which of the following is a Cartesian equation of the parametric curve determined by the
equations x(t) = cos2 (t), y(t) = sin(t), 0 ≤ t ≤ 2π.
(a) x2 + y 2 = 1
(b) xy = 1
(c) x2 + y = 1
(d) x + y 2 = 1.
Problem 4. A horizontal force of 12 lbs is acting on a box as it is pushed up a ramp that is 10 ft long
and inclined at an angle of 30◦ above the horizontal. Find the work done on the box.
(a) 60 ft. lbs.
√
(b) 60 3 ft. lbs.
√
(c) 12 2 ft. lbs.
(d) None of the above.