

InterviewSolution
Saved Bookmarks
1. |
Show that `|[1,alpha,alpha^2],[1,beta,beta^2],[1,gamma,gamma^2]|=(alpha-beta)(beta-gamma)(gamma-alpha)` |
Answer» `L.H.S. = |[1,alpha,alpha^2],[1,beta,beta^2],[1,gamma,gamma^2]|` Applying `R_1->R_1-R_3` and `R_2->R_2-R_3` `= |[0,alpha-gamma,alpha^2-gamma^2],[0,beta-gamma,beta^2-gamma^2],[1,gamma,gamma^2]|` `=(alpha-gamma)(beta-gamma)|[0,1,alpha+gamma],[0,1,beta+gamma],[1,gamma,gamma^2]|` `=(alpha-gamma)(beta-gamma)[beta+gamma - alpha-gamma]` `= (alpha-gamma)(beta-gamma)(beta-alpha)` `=(-1)(-1)(alpha-beta)(beta-gamma)(gamma-alpha)` `=(alpha-beta)(beta-gamma)(gamma-alpha) = R.H.S.` |
|