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Dictionary · D

Discriminant

The expression b2−4acb^2 - 4ac from the quadratic formula. Its sign tells you how many real solutions a quadratic equation has.

Example

For x2+2x+5=0x^2 + 2x + 5 = 0, the discriminant is 4−20=−16<04 - 20 = -16 < 0, so there are no real roots.

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