If y = logax has | y | 1 on X ∈ [2, + ∞), then the range of a is______ ．

If y = logax has | y | 1 on X ∈ [2, + ∞), then the range of a is______ ．

① When a ＞ 1, y = logax is an independent increasing function, ∵ x ∈ [2, + ∞) ∵ y ＞ 0, ∵ y | = y ＞ 1, i.e. loga2 ＞ 1 = logaa, ∵ a ＜ 2 | 1 ＜ a ＜ 2. When 0 ＜ a ＜ 1, y = logax is an independent decreasing function, ∵ x ∈ [2, + ∞) ∵ y ＜ 0 | y | = - y ＞ 1, i.e. - loga2 ＞ 1 = logaa ∵ loga12 ＞ logaa} 1

It is known that for any real number x, the function f (x) satisfies f (- x) = f (x). If the equation f (x) = 0 has 2009 real solutions, then the sum of these 2009 real solutions is______ ．

Let f (x) = 0 be the real solution of x1, X2 , X2009, let x1 ＜ x2 ＜ If there is x0 such that f (x0) = 0, then f (- x0) = 0, ｜ X1 + X2009 = 0, X2 + x2008 = 0 ，x1004+x1006=0，x1005=0，∴x1+x2+… +So the answer is: 0

(1 / 2) the known function f (x) = (xCube / 3) - ax + B, where real numbers a and B are constants. If f (x) is an odd function on R, G (a) is the most significant function of F (x) in the interval [- 1,1]

The derivative of F (x) = xsquare-a.x ∈ [- 1,1], X & # 178; ∈ [0,1]. Because | a | ≥ 1, a ≤ - 1 or 1 ≤ A. when a ≤ - 1, xsquare-a > = 2. That is, f (x) is simple increasing. G (a) = f (- 1) = - 1 / 3 + A, when 1 ≤ A., xsquare-a

There are two piles of sand. The weight of the first pile is 2.5 times that of the second pile. The weight of the first pile is 10.5 tons more than that of the second pile
How many tons each of the two piles of sand
The master worker planned to process a batch of machine parts. A total of 424 parts were processed in the first eight days, and the remaining parts were processed for another 12 days. How many parts need to be processed? (answer in proportion)

Suppose the second pile of sand has x tons, then the first pile has 2.5x tons, 2.5x-x = 10.51.5x = 10.5x = 7, 2.5 × 7 = 17.5 tons. A: the first pile has 17.5 tons, the second pile has 7 tons. A total of X parts need to be processed 424:8 = x: (8 + 12) 8x = 424 × 208x = 8480

According to life experience, the algebraic formula a + B is explained______ ；

The answer is not unique. For example, Xiaohua's age is a, his brother's age is B, and the total age of Xiaohua and his brother is (a + b)

1 to the third power + 2 to the third power + 3 to the third power of n

1^3+2^3+3^3+…… +n^3=[n(n+1)/2]^2
(n+1)^4-n^4=[(n+1)^2+n^2][(n+1)^2-n^2]
=(2n^2+2n+1)(2n+1)
=4n^3+6n^2+4n+1
2^4-1^4=4*1^3+6*1^2+4*1+1
3^4-2^4=4*2^3+6*2^2+4*2+1
4^4-3^4=4*3^3+6*3^2+4*3+1
.
(n+1)^4-n^4=4*n^3+6*n^2+4*n+1
What is the sum of all forms
(n+1)^4-1=4*(1^3+2^3+3^3...+n^3)+6*(1^2+2^2+...+n^2)+4*(1+2+3+...+n)+n
4*(1^3+2^3+3^3+...+n^3)=(n+1)^4-1+6*[n(n+1)(2n+1)/6]+4*[(1+n)n/2]+n
=[n(n+1)]^2
1^3+2^3+...+n^3=[n(n+1)/2]^2

The fruit shop brought in a batch of fruits, and the apples were 720 grams more than pears. The weight of apples was 1.8 times that of pears. How many grams of apples and pears were there?

If the pear is x, then the apple is 1.8x, and 1.8x-x = 720. If x is 900, then the pear is 900 and the apple is 16200

The apprentice finished 40% of the total number of parts. The master processed 80 more parts than the apprentice. How many parts did the master process?
The apprentice finished 40% of the total number of parts. The master processed 80 more parts than the apprentice. How many parts did the master process?

1-40% = 60%, 60% - 40% = 20%, 80 / 20% = 400, 400 * 60% = 240, 240 processed by master

What is the phase relationship between voltage and current in pure resistance, pure inductance and pure capacitance AC circuits?

In AC circuit, pure resistance, the phase of voltage and current is the same; pure inductance, the phase of voltage is 90 degrees ahead of the phase of current; pure capacitance, the phase of current is 90 degrees ahead of the phase of voltage

A holiday travel agency organized 36 tourists to travel by car. There are two kinds of cars that can be rented: one is for 8 people in each car, and the other is for 4 people in each car. It is required that the rented car should not leave empty seats, but it should not be overloaded
If the rent of an 8-seat car is 300 yuan / day and that of a 4-seat car is 200 yuan / day, please design a car rental scheme with the least rent and explain the reasons

Use four eight person cars, one four person car! It costs the least