AP EAMCET202422 May 2024Evening ShiftMathematicsQuadratic EquationActual
The set of all real values ' a ' for which -1 2 x^2+a x+2 x^2+x+1 3 holds for all real values of x is
Options
- A(-7,5)
- B(5, )
- C(1,5)
- D(- , 1)
Correct answer
C. (1,5)
Step-by-step solution
aligned & -1 2 x^2+a x+2 x^2+x+1 3 & Consider -1 2 x^2+a x+2 x^2+x+1 3 x^2+(a+1) x+3 0 & D 0 (a+1)^2-36 0 a^2+2 a-35 0 aligned (a+7)(a-5) 0 a (-7,5) ...(i) aligned & Also, 2 x^2+a x+2 x^2+x+1 3 -x^2+(a-3) x-1 0 & D 0 (a-3)^2-4 0 aligned a^2-6 a+5 0 (a-1)(a-5) 0 a (1,5) ...(ii) So, from (i) and (ii), a (1,5)