Equations of Lines in 3D

April 30, 2008

Let l be the line represented by the symmetric equations

\displaystyle\frac{x-2}{4} = \frac{y+3}{-2}=\frac{z-1}{7}

1. Find the point of intersection of l and the plane 5x-y+2z=12.

2. Find the distance between P(0,1,0) and l.

3. The acute angle between l and the line m: \hspace{.3in} x=1+t; \hspace{.2in} y=3-2t; \hspace{.2in} z=4t.

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Linear Independence

April 6, 2008

Let V be a finite vector space over the set of rationals, and F be a linear transformation from V to V. Suppose x, y and z are vectors in V such that

(i) F(x) = y

(ii) F(y) = z

(iii) F(z) = x+y

Suppose x is nonzero. Show that x, y and z are linearly independent vectors.

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