Definitions Flashcards
linearly dependent
The vectors {x1, x2, . . . , xm} in vector space V are linearly dependent if there exists a non-trivial linear combination of these vectors
such that it is equal to zero
proposition of linear dependence
Vectors {x1, x2, . . . , xm} in vector space V are linearly
dependent if and only if at least one of these vectors is expressed via linear
combination of other vectors:
define basis
Let V be n-dimensional vector space. The ordered set {e1, e2, . . . , en} of n linearly independent vectors in V is called a basis of the vector space V .
define scaler product
Scalar product in a vector space V is a function B(x, y)
on a pair of vectors which takes real values and satisfies the the following conditions:
(symmetricity condition)
(linearity condition)
(positive-definiteness condition)
define dimension
Vector space V has a dimension n if there exist n linearly independent vectors in the vector space
define orthonormal basis
ei such that they satisfy δij
explain what is meant by two bases having the same orientation?
We say that two bases {e1, . . . en} and {e1, . . . en} in V have
the same orientation if the determinant of transition matrix (1.39) from the first basis to the second one is positive: det T > 0.
Euler theorem ?
P = orthogonal and preserves orientation. then it is a rotation w.r.t θ and axis l. P(N) = N trP = 1 +2cos(θ)
define a differential 1-form
is a function on tangent vectors of E^n such that it is linear at each point:
ω(r, λv1 + μv2) = λω(r, v1) + μω(r, v2)
area of a parallelogram ?
S(x,y) = S(Π(x,y)) = |x×y| = |x|•|y||sinθ|
volume of a parallelpiped ?
V({a,b,c}) = |a•(b×c)|
velocity vector?
v(t) = dr/dt
define equivalent curve?
r1(t):(a,b)→E^n & r2(t):(c,d)→E^n are equivalent if there exists reparameterisation map t(τ):(a,b)→(c,d) such that r2(τ) = r1(t(τ))
define orientation of curves
two curves have opposite orientation if their reparameterisation t(τ) has a negative t’(τ)
ω?
? df = ∂f/∂x.dx + ∂f/∂y.dy