2012 NJC P1 Q2
2012 NJC P1 Q2 Relative to the origin $O$, the position vectors of the points $A$, $B$ and $P$ are $-mathbf{i}-3mathbf{j}+2mathbf{k}$, $5mathbf{i}+2mathbf{k}$ and $left( 1+2lambda right)mathbf{i}+left( lambda -2 right)mathbf{j}+2mathbf{k}$ respectively,