BITSAT2021MathematicsQuadratic EquationActual
Find the value of a such that the sum of the squares of the roots of the equation x²-(a-2) x-(a+1)=0 is least.
Options
- A4
- B2
- C1
- D3
Correct answer
C. 1
Step-by-step solution
Let , be the roots of the equation. + =a-2 and =-(a+1) Now, ²+ ²=( + )²-2 =(a-2)²+2(a+1)=(a-1)²+5 ²+ ² will be minimum if (a-1)²=0 , i.e. a=1 .