Given that the symmetry axis of the image is a straight line x = - 1, and the image passes through points (1,7), (0, - 2), the analytic expression of quadratic function is obtained

Given that the symmetry axis of the image is a straight line x = - 1, and the image passes through points (1,7), (0, - 2), the analytic expression of quadratic function is obtained

Let the analytic expression of the function be y = ax & # 178; + BX + C
According to the meaning of the title:
7=a+b+c
-2=c
-b/2a=-1
The solution is a = 3, B = 6, C = - 2
So the analytic formula is y = 3x & # 178; + 6x-2

The quadratic function y has a maximum value of 4, and the image passes through (5,6), and the axis of symmetry is a straight line x = 3

y=a(x-b)²+c,a

Given that (2,5), (4,5) are two points on the parabola y = ax ^ 2 + BX + C (a ≠ 0), then the axis of symmetry of the parabola is a straight line?

When x = 2 and x = 4, y is equal
So the axis of symmetry is x = (2 + 4) / 2 = 3

Given that the parabola y = ax & # 178; + BX + C (a ≠ 0) passes through two points (0,1) and (2-3), if the axis of symmetry is x = - 1, the analytical formula of the parabola is obtained
Urgent need

y=y(x)
y(0)=c=1
y(2)=4a+2b+1=-3
Axis of symmetry x = - B / (2a) = - 1
a=-1/2,b=-1