When x=0, y=c= 1.4.

When x= 1, y = a+b+c > 0 3 error

When x=4, y= 16a+4b+ 1.4=0. At the same time, the root of this image is positive and negative. From David's theorem, we can know that

The symmetry axis is on the right side of the Y axis, so the other one should be greater than -4, so the product of the two is greater than-16. According to David theorem, C/A >; - 16 a & lt； -780 1 correct

Choose C.

(7)

K

Then the symmetry axis of the quadratic function is -2 and the opening is d.

(8)

According to the meaning of the question, the quadratic function is open downward, then

x=0 y=c=-2

When x= 1, y = a+b+c > 0a+b & gt； 2 3 error

When x=2, y = 4a+2b+c < 02a+b <; 1 1 error

The product of two roots =c/a is greater than 0 and less than 2 a.

2a+b & lt； 1 a & lt； - 13a+b & lt； 0 2 error

choose one