算法基本语句(第二课时)(5)

QBASIC程序：INPUT “请输入一元二次方程的系数a,b,c=:”;a,b,c d=b*b-4*a*c p = -b / (2 * a) q = SQR(ABS(d)) / (2 * a) IF d >= 0 THEN x1 = p + q x2 = p - q IF x1 = x2 THEN PRINT “只有一个实根：”;x1=x1 ELSE PRINT “有两个实根：”;“x1=”;x1,”x2=”;x2 END IF ELSE PRINT “没有实根” END IF END