AP EAMCET201921 Apr 2019Morning ShiftMathematicsApplication of DerivativesActual

If the function f(x)=a x^3+b x^2+11 x-6 satisfies the conditions of Rolle's theorem in [1,3] and f^ (2+ 1 3 )=0 , then a+b=

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Correct answer

A. -5

Step-by-step solution

Given, f(x)=a x^3+b x^2+11 x-6 satisfies the Rolle's theorem in [1,3] . So, f(1)=0 and f(3)=0 array lrlrl and & & 27 a+9 b+27 & =0 & & 9 a+3 b+9 & =0 array From Eq. (i), we get a+b=-5

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