theorem Th1: :: POLYEQ_4:1

for a, b, c being Real st b / a < 0 & c / a > 0 & delta (a,b,c) >= 0 holds
( ((- b) + (sqrt (delta (a,b,c)))) / (2 * a) > 0 & ((- b) - (sqrt (delta (a,b,c)))) / (2 * a) > 0 )