Question: Does ax = bx imply a = b in any vector space? Justify. Let v = (a1,a2):a1,a2∈f where f is field. Define addition of elements of v coordinate wise, and for c∈f and (a1,a2)∈V . Define c(a1,a2)=(a1,0). Is vector space over F with these operations? Justify your answer by taking all condition of vector space.
Solution: In any vector space ax = bx implies that a = b false
It is only true if we take x = 0
i.e ; ax = bx \
x(a – b) = 0 either x = 0 or ( a-b) = 0
take x = 0 and any a≠b for x.
Let us suppose (a1,a2),(b1,b2)∈V then
Vs1:(a1,a2)+(b1,b2)=(a1+b1,a2+b2)=(b1+a1,b2+a2)=(b1,b2)+(a1,a2)
Vs2:[(a1,a2)+(b1,b2)]+(c1,c2)=(a1,a2)+[(b1,b2)+(c1,c2)]∀(c1,c2)∈f
Vs3:∃(d1,d2)∈V s.t (a1,a2)+(d1,d2)=(a1,a2)
(a1,a2)+(0,0)=(a1,a2)
(d1,d2)=(0,0)
Vs4:∀(a1,a2)∈V∃(−a1,−a2)∈V
s.t (a1,a2)+(−a1,−a2)=(0,0)
Vs5:∀∈F1.(a1,a2)=(a1,0)=(a1,0)≠(a1,a2)
Hence vs5 does not satisfy.
Vs6:∀x,y∈F xy(a1,a2)=x(ya1,0)
Vs7:∀x,y∈F
(x+y)(a1,a2)
= [(x+y)a1,0]
= [xa1+ya1,0]
= (xa1,0)+(ya1,0)
Vs8:∀x∈f
x[(a1,a2)+(b1,b2)]
=x[a1+b1,a2+b2]
=[x(a1+b1),0]
=(xa1,0)+(xb1,0)
=x(a1,a2)+x(b1,b2)\
Vs5 does not satisfy it is not vector space.
Question: Does ax = bx imply x = y in any vector space? Justify. Let v denote the set of ordered pairs of real numbers.if (a1,a2) and (b1,b2) are element of v and c∈R , define (a1,a2)+(b1,b2)=(a1.b1,a2+b2) and c(a1,a2)=(a1,ca2). Is v a vector space over R with these operations ? Justify your answer by showing all conditions of vector space.
Solution:
In any vector space ax = ay implies that x = y is false.
It is only true if we take a = 0
i.e; ax = ay a(x – y) = 0∈V
either a = 0 , or ( x – y) = 0 if we take a = 0 and any x ≠ y for a.\
Second part
Here v denote the set of ordered pairs of real numbers. If (a1,a2)and (b1,b2) are element of v and c∈R,define (a1,a2)+(b1,b2)=(a1.b1,a2+b2) and c(a1,a2)=(a1,c.a2).
Vs1:(a1,a2)+(b1,b2)=(a1.b1,a2+b2)=(b1.a1,b2+a2)=(b1,b2)+(a1,a2)
Vs2:∈[(a1,a2)+(b1,b2)]+(c1,c2)=(a1.b1,a2+b2)+(c1,c2)\
= (a1.b1.c1,a2+b2+c2)=(a1,a2)+(b1.c1,b2+c2)=(a1,a2)+[(b1,b2)+(c1,c2)]
Vs3:∃(d1,d2)∈V
s.t (a1,a2)+(d1,d2)=(a1,a2)
Or,(a1.b1,a2+b2)=(a1,a2)⇒a1.b1=a1⇒b1=1
Also,a2+b2=a2⇒b2=0
Hence (d1,d2)=(1,0)
so, (a1,a2)+(d1,d2)≠(a1,a2)
vs3 does not satisfy.
Vs4:∀(a1,a2)∃(−a1,−a2)∈V
s.t (a1,a2)+(−a1,−a2)=[a1.(−a1),b1+(−b1)]=(−a21,0)≠0
Hence vs4 also not satisfy.
Vs5:for1∈R1.(a1,a2)=(a1,1.a2)=(a1,a2)
Vs6:∀x,y∈R
xy(a1,a2)=x(a1,ya2)=x[y(a1,a2)
Vs7:∀x,y∈R
(x+y)[(a1,a2)+(b1,b2)]=(x+y)(a1,a2)+(x+y)(b1,b2)
L.H.S = (x+y)(a1.b1,a2+b2)
= [a1.b1,(x+y)(a2+b2)]
=[a1.b1,(x+y)a2+(x+y)b2]
R.H.S = [a1,(x+y)a2]+[b1,(x+y)b2]
= [a1.b1,(x+y)a2+(x+y)b2]
L.H.S = R.H.S
Vs8:∀x∈R
x[(a1,a2)+(b1,b2)]=x(a1,a2)+y(b1,b2)
L.H.S
= x[a1.b1,a2+b2]
= [a1.b1,x(a2+b2)]
= [a1.b1,xa2+xb2]
R.H.S
= (a1,xa2)+(b1,xb2)=(a1.b1,xa2+xb2)
L.H.S = R.H.S
Here vs3 and vs4 are not satisfy. Hence it is not vector space.
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