1. what (5 pts) True or False and and justify to get full points (a) A vector in
ID: 2961215 • Letter: 1
Question
1. what (5 pts) True or False and and justify to get full points
(a) A vector in R4 comprises 4 complex numbers
(b) A dot product between two vectors results in vector that is perpendicular to the other two.
(c) In a Cylindrical co-ordinate system all unit vector are position invariant
(d) If Ax = 0 then x lies in the null space of A
(e) The sum of the column rank and the row rank of a m x n (m is not equal to n) matrix is n+m
2) Answer all:
(a) Let the unit vectors be denoted by ^e1 = (1, 0) and ^e2 = (0, 1). Express the vector a = (4, 5) in terms of these unit vectors.
b) Suppose the unit vectors are ^e1 = (1, 1) and ^e2 = (-1, 1) express a = (4, 5) in terms of these unit vectors.
(c) Vectors in R4 are given as a = (1, 2,3, 9)and b = (3, 4, 2, 5). Find the angle between the two vectors.
(d) Suppose the inner product is defined as (a) under multiplication (b) = a1b1 + 5a2b2 + a3b4 - a4b3. Does this define a vector space?
Explanation / Answer
1) F may be real numbers
b)F dot product is scalar quantity
3) F co ordinate are (rcos theta , r sin theta , z ) it depends upon z
4) T by defination of null space
5) F it may be less than m+n
2)
A)4e1+5e2
B) a*(1,1)+b(-1,1) =(4,5)
a-b=4
a+b=5
so, 2a=9
a=4.5
b= 4.5-4=.5
so answer is 4.5e1+.5e2
c) a.b = a*b*cos theta
a= (9.74)
b= 7.34
1*3+2*4+3*2+9*5 = 9.74*7.34 cos theta
theta = 30
d)yes it is multiplication of a row matrix and a column matrix
row matrix= (a1,a2,a3,a4)
and column matrix = (b1,5b2,b4,-b3)
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