The image of quadratic function in junior high school mathematics The image of quadratic function y = ax & # 178; + BX + C passes through the opening of (1,0) and (0,1), and the symmetry axis is on the left side of y-axis, and the minimum value of a & # 178; + B is obtained

The image of quadratic function in junior high school mathematics The image of quadratic function y = ax & # 178; + BX + C passes through the opening of (1,0) and (0,1), and the symmetry axis is on the left side of y-axis, and the minimum value of a & # 178; + B is obtained

If the image passes through the (1,0) and (0,1) symmetry axes and is on the left side of the y-axis, the opening direction must be downward. You have the wrong title. Are you sure
If you don't look at the image, the answer is:
Because (1,0) and (0,1)
So we can get the following result by taking it into the function formula:
a+b+c=0
a+b=-1
A + B = - 1
c=1
So we can get b = - 1-A
So a ^ 2 + B = a ^ 2-a-1
The topic is transformed into the problem of finding the maximum value of quadratic function a ^ 2-a-1
Let g (a) = a ^ 2-a-1
The formula is g (a) = (A-1 / 2) ^ 2-4 / 5
The minimum value is - 4 / 5
Now your topic is wrong, because if the symmetry axis is to the left of the Y axis, then - B / 2A