Given the image of quadratic function y = AX2 + BX + C, we try to explain the symmetry axis of this function image when x = 2 through a (0, a) B (1, - 2A) It is known that the image of quadratic function y = AX2 + BX + C passes through a (0, a) B (1, - 2A) (1) Try to explain the symmetry axis of this function image when x = 2; (2) Based on the available information, can you find the analytic expression of quadratic function in the title? (1) Ask already know

Given the image of quadratic function y = AX2 + BX + C, we try to explain the symmetry axis of this function image when x = 2 through a (0, a) B (1, - 2A) It is known that the image of quadratic function y = AX2 + BX + C passes through a (0, a) B (1, - 2A) (1) Try to explain the symmetry axis of this function image when x = 2; (2) Based on the available information, can you find the analytic expression of quadratic function in the title? (1) Ask already know

a=c,
-2a=a^2+b+c,
x=2=-b/2a,
b=-4a,c=a,
-2a=a^2-4a+a,
a(a-1)=0,
a=1,a≠0.
c=1,b=-4.
That is, y = x ^ 2-4x + 1