may i know, given that A is the basis of (a1,a1,a) , B is the basis of )b1,b2,b3)

is

b1=a1-a3

b2=a1-a2

b3=a1+a1+a3

the transitition matrix from A to B or from B to A? i thought this was the transition matrix from A to B but the answers in my notes seems to suggest otherwise