99 Percentile Qs Bank for JEE MainMathematicsDeterminants
If x - 4 2 x 2 x 2 x x - 4 2 x 2 x 2 x x - 4 = A + B x x - A 2 , then the ordered pair ( A , B ) is equal to
Options
- A4, 5
- B- 4 , - 5
- C- 4 , 3
- D- 4 , 5
Correct answer
D. - 4 , 5
Step-by-step solution
x - 4 2 x 2 x 2 x x - 4 2 x 2 x 2 x x - 4 = A + B x x - A 2 Put x = 0 ⇒ - 4 0 0 0 - 4 0 0 0 - 4 = A 3 ⇒ A = - 4 x - 4 2 x 2 x 2 x x - 4 2 x 2 x 2 x x - 4 = B x - 4 x + 4 2 1 - 4 x 2 2 2 1 - 4 x 2 2 2 1 - 4 x = B - 4 x 1 + 4 x 2 Put x → ∞ ⇒ 1 2 2 2 1 2 2 2 1 = B ⇒ B = 5