chapter 2 Flashcards
scalar product/Euclidean inner product
= u1v1 + u2v2
norm
||v|| = ^1/2
angles between vectors
=||v||·||w||cos(v,w)
two vectors are perpendicular iff..
their inner product vanishes
cauchy-schwarz
|<u>| ≤ ||u||×||v|| with equality iff u,v collinear</u>
three vectors are linearly dependent if..
one can be written as a combination of the other two
three vectors are linearly independent if..
gaussian elimination provides single solution of all coefficients = 0 (trivial)
a linearly independent family of Rn contains _ vectors
a linearly independent family of Rn contains at most n vectors
the span of a set of vectors..
..is the set of all of their linear combinations
a spanning family of Rn contains _ vectors
a spanning family of Rn contains at least n vectors
basis of Rn is..
a family of vectors such that every vector of Rn can be written uniquely as a linear combination of the family
a family is a basis if and only if..
both spanning and linearly independent (a linear combination both exists and is unique)
a basis of Rn contains _ vectors
a basis of Rn contains exactly n vectors