Question

已知抛物线y等于ax的平方加bx加c的系数满足关系式4a减2b加c等于零这条抛物线

Answer 1

4a-2b+c=0

2b=4a+c

令y=0,则：ax^2+bx+c=0

b^2-4ac

=(4a+c)^2/4-4ac

=4a^2+c^2/4+2ac-4ac

=4a^2-2ac+c^2/4

=4(16a^2-8ac+c^2)

=4(4a-c)^2≥0

所以,一定与x轴有两个交点