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MathsHardMCQ2023 · 30 Jan Shift 2

Q82.Let q be the maximum integral value of p in [0, 10] for which the roots of the equation x2 −px + 45 p = 0 are rational. Then the area of the region {(x, y) : 0 ≤y ≤(x −q)2, 0 ≤x ≤q} is (1) 243 (2) 25 (3) 125 (4) 164 3

What This Question Tests

This multi-concept question first requires finding the integral values of a parameter for rational roots, then uses this value to determine the area under a parabolic curve by definite integration.

Concepts Tested

Condition for rational roots (discriminant is a perfect square)Solving quadratic inequalitiesArea bounded by curves (definite integration)Vertex of a parabola

Formulas Used

D = b^2 - 4ac

∫ (f(x) - g(x)) dx

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