BITSAT2019MathematicsQuadratic EquationActual
In the real number system, the equation x + 3 - 4 x - 1 + x + 8 - 6 x - 1 = 1 has
Options
- ANo solution
- BExactly two distinct solution
- CExactly four distinct solution
- DInfinitely many solution
Correct answer
D. Infinitely many solution
Step-by-step solution
We have, x + 3 - 4 x - 1 + x + 8 - 6 x - 1 = 1 ( x - 1 ) 2 - 2 × 2 x - 1 + 4 + ( x - 1 ) 2 - 2 × 3 x - 1 + 9 = 1 ⇒   ( x - 1 - 2 ) 2 + ( x - 1 - 3 ) 2 = 1 ⇒   | x - 1 - 2 | + | x - 1 - 3 | = 1 ⇒   | x - 1 - 2 | + | x - 1 - 3 | = ( x - 1 - 2 ) - ( x - 1 - 3 ) We know that, If | x - a | + | x - b | = ( x - a ) - ( x - b ) then ( x - a ) ( x - b ) < 0 ∴   ( x - 1 - 2 ) ( x - 1 - 3 ) < 0 ⇒   2 < x - 1 < 3 ⇒ 5 < x < 10 ∴