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MHT CET202416 May 2024Morning ShiftMathematicsApplication of DerivativesActual

If y= a x+ b x^2+x has its extremum values at x=-1 and x=2 , then

Options

  1. Aa =2, ~b =-1
  2. Ba =2, ~b =- 1 2
  3. Ca =-2, ~b = 1 2
  4. Da =2, ~b = 1 2

Correct answer

B. a =2, ~b =- 1 2

Step-by-step solution

array ll & y=a x+b x^2+x & ~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...(i) array and ( d y ~d x )_ x=2 = a 2 +4 ~b +1=0 a+8 b+2=0...(ii) Solving (i) and (ii), we get a=2, b=- 1 2

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