Most Important Selected Qs for JEE AdvancedMathematicsDeterminants
If | array lll b+c & c+a & a+b c+a & a+b & b+c a+b & b+c & c+a array | 0 , where a, b, c R⁺- 0 , then a+b c is
Correct answer
2
Step-by-step solution
Let = | array lll b + c & c + a & a + b c + a & a + b & b + c a + b & b + c & c + a array | Operate : C ₁ C ₁+ C ₂+ C ₃ aligned & = | array lll 2(a+b+c) & c+a & a+b 2(a+b+a) & a+b & b+c 2(a+b+c) & b+c & c+a array |=2(a+b+c) | array lll 1 & c+a & a+b 1 & a+b & b+c 1 & b+c & c+a array | Operate: R₂ R₂-R₁ ; R₃ R₃-R₁ & D=2(a+b+c) | array lll 1 & c+a & a+b 0 & b-c & c-a 0 & b-a & c-b array | & =2(a+b+c) 1 . | array ll b-c & c-a b-a & c-b array | open w.r.t. R₁ aligned aligned & =2(a+b+c)[(b-c)(c-b)-(c-a)(b-a)]=2(a+b+c)