KCET2024MathematicsDeterminants
If A= | array ll x & 1 1 & x array | and B= | array lll x & 1 & 1 1 & x & 1 1 & 1 & x array | , then d B d x is
Options
- A3 A
- B-3 B
- C3 B+1
- D1-3 A
Correct answer
A. 3 A
Step-by-step solution
B= | array lll x & 1 & 1 1 & x & 1 1 & 1 & x array |= | array lll 1 & 1 & 1 0 & x & 1 0 & 1 & x array |+ | array lll x & 0 & 1 1 & 1 & 1 1 & 0 & x array |+ | array lll x & 1 & 0 1 & x & 0 1 & 1 & 1 array |= (x^2-1 )+ (x^2-1 )+ (x^2-1 )=3 (x^2-1 )=3 A [ A= | array ll x & 1 1 & x array |=x^2-1 ]