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Algebra readiness

Read quadratic roots and signs · Diagrams

Six discriminant and leading-coefficient cases

How roots and opening fit together

D = 4: two distinct real roots. The curve crosses the axis at −1 and 1.

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Read a quadratic in two checks

  1. Check the discriminant.
  2. Count the real roots.
  3. Use the opening to decide signs.
Six schematic parabolas: for D>0 both upward and downward curves cross the x-axis twice; for D=0 each touches it at its vertex; for D<0 the upward curve stays above and the downward curve below. D=b²−4ac. No coordinates are prescribed by the source.
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