COMEDK2019MathematicsDeterminants
If A= | array lll a₁ & b₁ & c₁ a₂ & b₂ & c₂ a₃ & b₃ & c₃ array | and B= | array ccc c₁ & c₂ & c₃ a₁ & a₂ & a₃ b₁ & b₂ & b₃ array | then
Options
- AA=-B
- BA=B
- CB=0
- DB=A²
Correct answer
B. A=B
Step-by-step solution
We have, aligned A &= | array lll a₁ & b₁ & c₁ a₂ & b₂ & c₂ a₃ & b₃ & c₃ array | &= | array lll a₁ & a₂ & a₃ b₁ & b₂ & b₃ c₁ & c₂ & c₃ array | &=(-) | array lll b₁ & b₂ & b₃ a₁ & a₂ & a₃ c₁ & c₂ & c₃ array | & [ |A|= |A^ T | ] &=(-)(-) | array lll c₁ & c₂ & c₃ a₁ & a₂ & a₃ b₁ & b₂ & b₃ array |= | array lll c₁ & c₂ & c₃ a₁ & a₂ & a₃ b₁ & b₂ & b₂ array |=B [R₁ R₃ ] aligned