Let even function f (x) satisfy f (x) = x ^ 3-8 (x is greater than or equal to 0), then {x f (X-2) > 0} is equal to? The answer is that a set X has two value ranges

Let even function f (x) satisfy f (x) = x ^ 3-8 (x is greater than or equal to 0), then {x f (X-2) > 0} is equal to? The answer is that a set X has two value ranges

Let x ≤ 0, then - x ≥ 0. And f (x) is even function
∴f(-x)=(-x)^3-8=f(x)
When x ≤ 0, f (x) = - x ^ 3-8
① When f (X-2) > 0
When I x > 2
The solution of (X-2) ^ 3-8 ＞ 0 is x ＞ 4
When Ⅱ x ＜ 2
-The solution of (X-2) ^ 3-8 ＞ 0 is x ＜ 0
② When f (X-2) < 0
Ⅰx＞2
The solution of (X-2) ^ 3-8 ＜ 0 is x ﹤ 4 ﹤ 2 ﹤ x ﹤ 4
Ⅱx＜2
-The solution of (X-2) ^ 3-8 ＜ 0 leads to the contradiction between X ＞ 0 and the condition
To sum up, {x f (X-2) > 0} = {x, x > 2, x < 0}

If f (x) = (A-2) x & # 178; + (A-1) x + 3 is an even function, then the increasing interval of the function——————
Why satisfy the condition that function is even function is A-1 = 0

The condition of even function is f (x) = f (- x)
Then (A-2) x Λ 2 - (A-1) x + 3 = (A-2) x Λ 2 + (A-1) x + 3
It can be concluded that - (A-1) x = (A-1) X
1-a=a-1
a=1

If the derivative of function f (x) at x = m is a, find the value of [f (M + △ x) - f (M - △ x)] / △ x when △ x → 0;
When t → 0, [f (M + 4T) - f (M + 5T)] / T

f'(m)=lim(x->m)f(x)=mlim(△x->0)[f(m+△x)-f(m-△x)]/△x=2lim(△x->0)[f(m+△x)-f(m-△x)]/[m+△x)-(m-△x)=2f'(m)=2Alim(t->0)[f(m+4t)-f(m+5t)]/t=-lim(t->0)[f(m+4t)-f(m+5t)]/[(m+4t)-m+5t)]=-f'(m)=-A...

Which great God helped me to do a few series questions 1, 49, 30, 38, () 37, 18, 2, 1 / 3, 7 / 10, 13 / 17, 19 / 24, 25 / 31, 3, 1, 4, 4, 16 ()

The second answer is 31 / 38. The numerator is an arithmetic sequence with a tolerance of 6, and the denominator is an arithmetic sequence with a tolerance of 7

A number minus its product with its reciprocal, the difference is 1, the number is___ ．

According to the analysis, this number minus itself and its reciprocal product, the difference is 1, so the product is 1, the difference is 1, then this number is 2, that is 2-2 × 12 = 1

3x-5 = 2x + 7 to solve the equation

3x-5=2x+7
3x-2x=5+7
x=12

5 out of 7 * 4 out of 9 + 3 out of 7 * 5 out of 9

No
5 out of 7 * 4 out of 9 + 3 out of 7 * 5 out of 9
=20 out of 63 + 15 out of 63
=35 out of 63
=5 out of 9

Write 5 rational numbers, so that there are 3 integers, 2 fractions, 2 positive numbers and 2 negative numbers

There are many answers to this question, but all the answers should contain 0, because 0 is neither positive nor negative. If you know this, it's easy to write others. You can write two integers and two fractions at will, and then find two numbers and a negative sign, for example, 1,0,2, - 1 / 2, - 2 / 3

What kind of equation can be used to calculate the higher order equation of one variable

Factorization does work
However, for the complex coefficients of the unary 1-th, 2-th, 3-th, 4-th equation can be solved
There is no general formula for finding roots over 5 times
This was discovered and proved by great mathematicians in the 17th century

It is possible to set unknowns
In the "world reading day" series of reading activities, students in class 5 (1) and class 5 (2) read a total of 184 books. The number of books read by students in class 5 (1) is 1.3 times that of class 5 (2). How many books have students in the two classes read?

The number of books in class 5 (2) is X
x+1.3x=184
（1+1.3）x=184
2.3x=184
2.3x/2.3=184/2.3
x= 80
80*1.3=104
A: Class 5 (2) students read 80 books, class 5 (1) students read 104 books
Please give me points!