Question 12***+A vector has coordinates \((1,2)\) in \(B=((1,0),(1,1))\). Find its standard coordinates and explain the basis dependence.
Question 15****+For which \(k\) does \(B_k=((1,1),(1,k))\) allow unique coordinates for every vector in \(\mathbb R^2\)?
Question 16****+For which \(t\) is \([(1,2,3)]_{B_t}\) defined for every target vector when \(B_t=((1,0,0),(0,1,0),(1,1,t))\)?
Question 17****+For \(B=((1,0),(1,k))\), find \([(x,y)]_B\) when possible and state the condition on \(k\).
Question 20*****Explain why coordinates describe the same vector, not a different physical displacement.