12-240/Classnotes for Thursday September 27: Difference between revisions
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{{12-240/Navigation}} |
{{12-240/Navigation}} |
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'''Vector Spaces''' |
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In this course, we will be focusing on both a practical side and a theoretical side. |
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== Vector space axioms == |
== Vector space axioms == |
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''(Quick recap)'' |
''(Quick recap)'' |
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VS1. x + y = y + x |
VS1. x + y = y + x |
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VS2. (x + y) + z = x + (y + z) |
VS2. (x + y) + z = x + (y + z) |
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VS3. 0 vector |
VS3. 0 vector |
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VS4. + inverse -> - |
VS4. + inverse -> - |
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VS5. 1x = x |
VS5. 1x = x |
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VS6. a(bx) = (ab)x |
VS6. a(bx) = (ab)x |
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VS7. a(x + y) = ax + ay |
VS7. a(x + y) = ax + ay |
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VS8. (a+b)x = ax + bx |
VS8. (a+b)x = ax + bx |
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== Theorems == |
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1.a x + z = y + z => x = y |
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1.b ax = ay, a != 0, => x = y |
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1.c ax = bx, x != 0, => a = b |
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2. 0 is unique. |
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3. Additive inverse is unique. |
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4. 0_F * x = 0_V |
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5. a * 0_V = 0_V |
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6. (-a) x = -(ax) = a(-x) |
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7. cx = 0 <=> c = 0 or x = 0_V |
Revision as of 20:26, 27 September 2012
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Vector Spaces
Vector space axioms
(Quick recap)
VS1. x + y = y + x
VS2. (x + y) + z = x + (y + z)
VS3. 0 vector
VS4. + inverse -> -
VS5. 1x = x
VS6. a(bx) = (ab)x
VS7. a(x + y) = ax + ay
VS8. (a+b)x = ax + bx
Theorems
1.a x + z = y + z => x = y
1.b ax = ay, a != 0, => x = y
1.c ax = bx, x != 0, => a = b
2. 0 is unique.
3. Additive inverse is unique.
4. 0_F * x = 0_V
5. a * 0_V = 0_V
6. (-a) x = -(ax) = a(-x)
7. cx = 0 <=> c = 0 or x = 0_V