(2) The function y=2f2(x)+2bf(x)+ 1 about x has eight different zeros.
If △=0, then f(x) has a value such that y=0. Let this value be f(x)=m, which means that there are eight different questions according to the meaning.
The value of x makes f(x)=m, which is impossible from f(x) image;
If △ > 0, that is, f(x) has two values, so y=0. Let these two values be: f(x)=k and f(x)=h, according to the meaning of the question.
That is, there are four x values that make f(x)=k and four x values that make f(x)=h, so it is possible to combine f(x) images.
, that is, at 0
So: the original problem can be transformed into the following questions:
The function f(x) = y = 2x 2+2bx+ 1 There are two different intersections between x (x is equivalent to F (x) in the original formula) and X axis.
And the intersection points are all within (0, 1), so find the range of B.
As long as the following four conditions are met:
△& gt; 0 0 & lt-2b/(2 * 2)& lt; 1 (symmetry axis) F(0)>0 F( 1)>0
Simultaneous solution: -3/2
A postgraduate information of architecture in South China University of Technology
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