Ask for this question, ask the great god to teach this question

Answer: From the known:

f '(x)=x^2+ax+a

Because a,b are two different extreme points of the function f(x).

So x2+ax+a=0 has two different roots, i.e., x1, x2 and x1+x2= -a, x1x2=a

i.e. a 2 -4a >0

Get a<0 or a>4

The slope of ab is [f(x1) -f(x2)] (x1 -x2).

1/3(x1^3 -x2^3)+1/2a(x1^2 -x2^2)+a(x1 -x2) ]/ (x1 -x2)

1/3 [(x1+x2)^2 -x1x2]+1/2a(x1+x2)+a

1/3[( a)^2 -a]+1/2a( -a)+

1/6)a^2+(2/3)a

Because the slope of the straight line ab is not less than -2

So (-1 6)a 2+(2 3)a >= -2

The solution is -2 <= a <= 6

In summary, -2<=a<0 or 4f(x) is the first derivative f'(x)=-2*(2x^2 - tx -2)/(x^2 + 1)^2

f'The denominator of (x) is everstable at 0, and the part where the numerator is positive is exactly [ ,

So f'(x) in the interval [ , Shangheng is 0

So f(x) increases monotonically on the interval [ , .

So a=f( )=(4 -t) ( 2 +1), b=f( )=(4 -t) ( 2 +1).

g(t)=a-b=[4αβ(4(α-t(α-/(α^2β^2+α^2+β^2+1)

Since , are the two roots of the equation, + =t 2, *=-1

=-sqrt(α^2 + 2 -2αβ)=-sqrt[(α2-4αβ]=-[sqrt(t^2+16)]/2

Bring in g(t) = sqrt(t2 +16).

And because the equation has two real roots, delt=t 2 +16 Evergrande is 0

So when the minimum value of g(t) is t=0, g(0)=4

（100x4－248）➗（4-2）

76 chickens one by one.

Rabbit one one 100 76 = 24.

Standard chickens and rabbits in the same cage, 100 heads, assuming that they are all chickens, then it is 200 feet, if a rabbit is replaced with a chicken, then there are two more feet, now 248 feet, 48 more, 48 2 = 24, indicating that 24 chickens were replaced with 24 rabbits, then there are 24 rabbits, and there are 100-24 = 76 chickens.

First. Question 1: 13 -24 square centimeters.

First. Question 2: 24 square centimeters.

Question 2: Square centimeters.

Question 3: 40 square centimeters.