Question 1
1.1 Let u = 2i + 2j + 3k and v = -i + j + 4k.
a) Find the unit vector ii in the direction of u.
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b) Find the projection vector of u onto v.
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b) Find the angle (in degrees) between u and v. Give you answer correct to 2 d.p. [7]
1.2 Determine the area of parallelogram whose adjacents sides are a = 2i - 4j + 5k and b =
i - 2j - 3k. Leave your answer in surd form.
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1.3 If A and B are vectors, then show that (A - B) x (A+ B) = 2(A x B)
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Question 2
2.1 Let A be a square matrix and let
a) Find S+P.
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b) Show that S is symmetric and P is skew-symmetric.
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c) If A is symmetric, then show that S = A and P = 0.
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1
2.2 Conside, the m,t,ix A (
~5 ) .
a) Use the Co.factor expa.ns-ion method. a.long the second cul·urnn to evaluate the cletenui-
nant of A.
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b) Is A invertible? If it is, Use the Gauss-Jordan Elimination method to find A- 1 . [14]
c) Find det (3(2A)- 1).
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Question 3
Determine whether or not the vector (-1,1,5) is a linear combination of the vectors (1,2,3), (0,1,4)
and (2,3,6).
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Question 4
Let W= {(x,y,z) E~ 3[3y+2z=0}.
a) Verify that W is a subspace of ~ 3 .
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b) Find a basis for W.
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