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Probability 6.0/10

Real Roots at Random

The coefficients a, b, c are chosen independently and uniformly from [0, 1]. What is the probability that the quadratic ax² + bx + c = 0 has real roots? Give an exact closed form, or a decimal rounded to 4 places.

Related problems & prerequisites

Worth solving first

Source: Classic geometric-probability exercise in wide circulation; no traceable original source. Statement written for AxiomIQ.