SOLUTIONS TO HOMEWORK #3, MATH 54 SECTION 001, SPRING 2012

1 5. Plugging in x 1 = 0 and x 2 = 1 gives 2 4 b d f 3 5= 2 4 1 1 0 3 5, so the matrix is 2 4 1 1 2 1 1 0 3 5. To check, 2 4 1 1 2 1 1 0 3 5 x 1 x 2 really does equal 2 4 x 1 x 2 2x 1 + x 2 x 1 3 5 for all x 1 and x 2. 4. Ex. 2.1.2: In Exercises 1 and 2, compute each matrix sum or product if it is de ned. If an expression is unde ned, explain ... ................
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