AP EAMCET20224 Jul 2022Evening ShiftMathematicsQuadratic EquationActual
Difference between the corresponding roots of x 2 + a x + b = 0 & x 2 + b x + a = 0 is same and a ≠ b , then
Options
- Aa   +   b   -   4   = 0
- Ba   -   b   -   4   =   0
- Ca   -   b   +   4   =   0
- Da   +   b   +   4   =   0
Correct answer
D. a   +   b   +   4   =   0
Step-by-step solution
Let α ,   β   &   γ ,   δ are the roots of the equations x 2 + a x + b = 0 and x 2 + b x + a = 0 respectively. Therefore, α + β = - a α β = b Also, for the second equation γ + δ = - b γ δ   =   a Given that, α - β = γ - δ ⇒ α - β 2 = γ - δ 2 ⇒ α + β 2 - 4 α β = γ + δ 2 - 4 γ δ ⇒ a 2 - 4 b = b 2 - 4 a ⇒ a 2 - b 2 + 4 a -