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MHT CET202411 May 2024Evening ShiftMathematicsApplication of DerivativesActual

If y= a x+ b x^2+x has its extreme values at x=-1 and x=2 , then the value of ( a b + b a ) is

Options

  1. A- 7 4
  2. B- 15 4
  3. C- 17 4
  4. D- 5 4

Correct answer

C. - 17 4

Step-by-step solution

aligned & d y ~d x = a x +2 ~b x+1 ( ~d y ~d x )_ x=-1 =- a -2 ~b +1=0 & a =-2 ~b +1 & and ( d y ~d x )_ x=2 = a 2 +4 ~b +1=0 & -2 ~b +1 2 +4 ~b +1=0 & - b +4 ~b + 3 2 =0 & 3 ~b = -3 2 ~b = -1 2 and a =2 & ( a b + b a )= -17 4 aligned

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