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MathsMediumMCQ2015 · 10 Apr Online

Q81.If Rolle's theorem holds for the function f(x) = 2x3 + bx2 + cx, x ∈[−1, 1] at the point x = 12 , then 2b + c is equal to (1) 2 (2) 1 (3) −1 (4) −3

What This Question Tests

This question is a direct application of Rolle's Theorem. It requires applying the conditions that f(a) = f(b) and f'(c) = 0 at the given point 'c' to solve for the unknown coefficients and then calculate the required expression.

Concepts Tested

Conditions for Rolle's TheoremDifferentiation of polynomials

Formulas Used

f(a) = f(b)

f'(c) = 0

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