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Invariant correctness in mathematics
f(x)=( 1-a)x^2+(a- 1)x+3

1, when 1-a=0, that is, a= 1 and f(x)=2, the identity on [-2,2] is satisfied.

2. when 1-a >; 0 is a

The axis of symmetry is x= 1/2, which intersects with the positive semi-axis of Y-axis.

△=(a- 1)^2-4( 1-a)(3-a)& lt; 0

Get an a

So, a< this time, a

3. When 1-a

To satisfy the meaning of the question, you must:

f(0)= 3-a & gt; 0

f(-2)>0

f(2)>0

Get an a

So at this time 1

To sum up, the range of A is a < 9/7.