SOLUTION: Consider only vectors in R^3 Proof: if v dot w = 0 for all v, then w = 0 Please help, i tried through a counterexample and my professor didn't like it.

Algebra.Com
Question 436449: Consider only vectors in R^3
Proof: if v dot w = 0 for all v, then w = 0
Please help, i tried through a counterexample and my professor didn't like it.

Answer by robertb(5830)   (Show Source): You can put this solution on YOUR website!
It follows from the hypothesis that ==> . Only one vector has 0 magnitude, and that is the zero vector. Hence w is the zero vector.
RELATED QUESTIONS

Consider only vectors in R^3 Please help with this PROOF if u dot v = u dot w for all (answered by robertb)
Please help me ㅠㅠ help me 1)u×u>=0 and u×u=0 if and only if u=0 prove... (answered by lynnlo)
1)u×u>=0 and u×u=0 if and only if u=0 prove theorem? 2)Show that there are no vectors u... (answered by lynnlo)
1)u×u>=0 and u×u=0 if and only if u=0 prove theorem? 2)Show that there are no vectors u... (answered by lynnlo)
Please help. Thank you in advance Determine whether the vectors v and w are parallel... (answered by Fombitz)
If u, v and w are unit vectors and satisfy condition u + v + w = 0 then find u.v + u.w +... (answered by ikleyn)
Let u, v, and w be distinct vectors of a vector space V. Show that if {u, v, w} is a... (answered by khwang)
If addition of three vectors U, V and W is zero i.e. if U + V + W = 0 then UxV = VxW =... (answered by Alan3354,ikleyn)
Find the dot product v dot w if v = i + j and w = -i +... (answered by nabla)