Xiaohua, Xiaojun and Xiaogang are in a race. Xiaojun's speed is 1.2 times that of Xiaohua, and Xiaogang's speed is 108% of Xiaohua's. who is the first and who is the second?

Take Xiaohua's speed as unit 1
Speed of Xiaojun: 1 × 1.2 = 1.2
Xiaogang's speed: 1 × 108% = 1.08
Because 1.2 ＞ 1.08 ＞ 1
Therefore, Xiaojun is the fastest and the first
Xiaogang's speed was second, and he came in second
Xiaohua is the slowest and third

Xiaohua, Xiaojun and Xiaogang are in a race. Xiaojun's speed is 1.2 times that of Xiaohua. Xiaogang's speed is 108% of Xiaohua's. who is the first?

108% = 1.08
1.2 ＞ 1.08
So small army first

Xiaohua and Xiaogang each bought a basket of apples with the same amount of money
Xiaohua and Xiaogang each bought a basket of apples with the same amount of money. When they divided the apples, Xiaohua divided 6 kilograms more than Xiaogang. Therefore, Xiaohua had to give Xiaogang 30 yuan. How much yuan per kilogram?

6 △ 2 = 3kg
30 △ 3 = 10 yuan

Changjiang park has a new amusement project built by two British people. My Chinese knowledge has improved since one semester

Two new amusement projects have been set up in the Yangtze River Park with the help of the UK. Since one semester, my Chinese score has improved

First remove the brackets, and then merge the similar terms: (1) (x + Y-Z) + (X-Y + Z) - (X-Y-Z); (2) 3 (2x2-y2) - 2 (3y2-2x2)

(1) The original formula = x + Y-Z + X-Y + z-x + y + Z = x + y + Z; (2) the original formula = 6x2-3y2-6y2 + 4x2 = 10x2-9y2

Is the inverse function of y = e Λ x y = LNX or x = LNY?
Now I'm learning inverse function by myself, but the product of the derivative of exponential function and the derivative of its inverse function is - 1. I'm completely ruined

Y = ln (x) is an inverse function. Originally, the inverse function should be x = LNY, but people usually use X to represent the independent variable and y to represent the dependent variable, so y = ln (x) is used to represent the inverse function. The y value in the inverse function is the x value of the original function, and the x value of the inverse function is the y value of the original function

Xiao Ming is 128cm tall, Xiao Gang is 26cm taller than him, Xiao Li is 9cm shorter than him. How tall is Xiao Gang? How tall is Xiao Li?

128＋26＝154 128－9＝ 119
A: Xiaogang 154 Xiaoli 119

Given the function f (x) = ln (AX + 1) + 2 / (x + 1), where a > 0, we discuss the monotonicity of function f (x) at (0, + ∞)
Given the function f (x) = ln (AX + 1) + 2 / (x + 1), where a > 0. ① discuss the monotonicity of function f (x) in (0, + ∞). ② if the minimum value of function f (x) in [0, + ∞) is 2, find the value range of positive number a

f(x)=ln(ax+1)+2/（x+1）
Domain requirements: x > 0, and x > - 1 / A
f'(x)=a/(ax+1)-2/(x+1)^2
=[a(x+1)^2-2(ax+1)]/[(ax+1)(x+1)^2]
=(ax^2+a-2)/[(ax+1)(x+1)^2]
=a[x^2-(2/a-1)]/[(ax+1)(x+1)^2]
When a ≥ 2, 2 / A-10 = = > x ∈ (√ (2 / A-1), + ∞)
F (x) increasing interval (√ (2 / A-1), + ∞), decreasing interval (0, √ (2 / A-1))
②
If the minimum value of function f (x) on [0, + ∞) is 2, find the value range of positive number a
When a ≥ 2, 2 / A-1

On the concept of function limit
1. In a process, if f (x) and G (x) have no limit, then f (x) + G (x) have no limit, right?
2. If f (x) has a limit and G (x) has no limit, then f (x) g (x) has no limit, right?
Please explain the reason. It's better to have a proof process,

1 wrong
2 wrong
For example, f = x, g = - X
For example, f = 0, G has no limit

It is proved that there is a matrix P such that commutative matrices A and B are diagonalized at the same time

Here we can triangulate at the same time, but not diagonalize
The proof is also very simple, using the commutative matrix has a common eigenvector, and this eigenvector is extended to a set of bases
Consider the matrix of a and B under this set of bases, and then use mathematical induction
Note:
Of course, in fact, a and B are required to be exchangeable. If the country is strong, only rank (ab-ba) is needed

Xiaohua, Xiaojun and Xiaogang are in a race. Xiaojun's speed is 1.2 times that of Xiaohua, and Xiaogang's speed is 108% of Xiaohua's. who is the first and who is the second?