Decades: 1230s 1240s 1250s 1260s 1270s - 1280s - 1290s 1300s 1310s 1320s 1330s
Years: 1284 1285 1286 1287 1288 - 1289 - 1290 1291 1292 1293 1294
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... term b2 – 4ac is called the discriminant of the quadratic equation, because it discriminates between three qualitatively different cases: If the discriminant is ...