KCET2009MathematicsDeterminants
If | array ccc 1+ ² & ² & 4 2 ² & 1+ ² & 4 2 ² & ² & 4 2 -1 array |=0 and 0 < < 2 , then 4 is equal to
Options
- A3 2
- B0
- C-1 2
- D1 2
Correct answer
D. 1 2
Step-by-step solution
Given, | array ccc 1+ ² & ² & 4 2 ² & 1+ ² & 4 2 ² & ² & 4 2 -1 array |=0 Applying C ₁ C ₁+ C ₂ | array ccc 2 & ² & 4 2 2 & 1+ ² & 4 2 1 & ² & 4 2 -1 array |=0 Applying R ₂ R ₂- R ₁, R ₃ 2 R ₃- R ₁ aligned & | array ccc 2 & ² & 4 2 0 & 1 & 0 0 & ² & 4 2 -2 array |=0 & 2(4 2 -2-0)=0 & 2 = 1 2 & Now, 4 =1-2 ² 2 &=1-2 ( 1 2 )²= 1 2 aligned