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Column vectors |
2015-02-21 |
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jill pose la question : A has co- ordinates (7,-1) and B has co-ordinates (3,5).write these as column vectors Penny Nom lui répond. |
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A column and a sloped ceiling |
2011-06-10 |
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Tom pose la question : Hi! I am a woodworker who needs some help finding a formula. I have to make a cylinder shape column that butts up against a sloped ceiling using bending plywood. I need to figure out how to cut the shape on this flat piece of material. The diameter of the column is 54.375". The tallest point is 9 13/16" and the shortest point is 4 7/16". Any help would be greatly appreciated. Harley Weston lui répond. |
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The column space of a matrix |
2009-02-12 |
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John pose la question : Question from John, a student:
A=
1 1 0 0
1 1 0 0
0 0 1 0
0 0 1 1
B=
1 5 6
1 5 6
0 7 2
0 0 9
Is the space spanned by the columns of A the same as the space spanned by the columns of B? Harley Weston lui répond. |
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Two-column proof for a circle geometry problem |
2007-08-24 |
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Kendra pose la question : i have to prove that tangents to a circle at the endpoints of a diatmeter are parallel by stating whats given, whats to prove and a plane, then write a two column proof i dont understand this Stephen La Rocque lui répond. |
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Prove that a rhombus' diagonals are perpendicular |
2005-10-02 |
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Tania pose la question : How do you prove that a rhombus' diagonals are perpendicular using the 2 column proof method? Walter Whiteley lui répond. |
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Two matrix problems |
2005-03-30 |
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Sue pose la question : Question 1
Suppose all matrices in the equation below are square and invertible. Solve for x .
BA-1XB-1 + 2BA + In = 0 (the symbol "0" here denotes the matrix of all 0's in it)
Also, A-1 or B-1 is indicating inverse and "In" = for example, A-1 times A
I hope you understand the above. I have to show all the steps.
Question 2
Suppose we consider the set of all 2x2 matrices along with the operations of matrix addition and multiplication. Do they form a field? Why or why not?
I think the answer is no because under multiplication it is not commutative and not all square matrices are invertible. I not positive so I'd like some help. Penny Nom lui répond. |
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A matrix construction problem |
2005-03-14 |
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Marcelo pose la question : I want to know if is it possible to solve this problem:
I have an empty NxM matrix and I know totals (sum) by rows and totals by column.
Is there any algorithm to fill the matrix so that the summary of columns and rows gives the original values I have? Harley Weston lui répond. |
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