Zhang Hua and Li Ping have established a profound friendship

Zhang Hua and Li Ping have established a profound friendship

Established a deep friendship

The math teacher is Zhang Hua

Our math teacher is Zhang Hua
Adjusting word order: Zhang Hua is a math teacher

You must correct the purpose of your study in order to make greater progress

Correct learning attitude;
Set learning goals

Given the set a = [- 1,2], the complete set u = (- ∞, 3], find CUA =?

(- infinity, - 2) Union [2,3]

It is known that C is the midpoint of line AB, D is a point on CB, e is the midpoint of DB, if CE = 4, ad = 2 / 3 AB, the length of line AB is obtained
fast

It is known that C is the midpoint of ab
So: AC = 1 / 2Ab
And because: ad = 2 / 3AB
And AC + CD = ad
So: CD = ad-ac = 2 / 3ab-1 / 2Ab = 1 / 6ab
In addition: BD = AB ad = 1 / 3AB
And E is the midpoint of BD
Then de = 1 / 2bd = 1 / 6ab
To sum up, CE = CD + de = 1 / 6ab + 1 / 6ab = 1 / 3AB = 4cm
Then 1 / 3AB = 4cm
ab=12cm

On the mathematical definition of upper (lower) triangular matrix
Who can give me a complete mathematical definition of upper and lower triangular matrix!

Upper triangular matrix definition: 0 below the main diagonal. Lower triangular matrix: 0 above the main diagonal

Solve the equation x ^ (1 + LG x) = 100

x^(1+lgx)=100
lg[x^(1+lgx)]=2
(1+lgx)lgx=2
(lgx)²+lgx-2=0
(lgx-1)(lgx+2)=0
Lgx = 1, or lgx = - 2
So x = 10, or x = 0.01

The definite integral of x ^ 3 (SiN x) ^ 2 / x ^ 4 + 2x + 1 in [- 1,1]

Hello! The topic may be wrong, it should be x ^ 4 + 2x ^ 2 + 1! Because f (x) = x ^ 3 (SiN x) ^ 2 / (x ^ 4 + 2x ^ 2 + 1) = x ^ 3 (SiN x) ^ 2 / (x ^ 2 + 1) ^ 2, then f (- x) = - x ^ 3 (SiN x) ^ 2 / (x ^ 2 + 1) ^ 2 = - f (x), so the integrand is an odd function, and the integral interval is a symmetric interval, so

If we multiply any two numbers in - 5, - 2,2, the maximum product is

Take - 5 and - 2, their product is: (- 5) × (- 2) = 10, then the product is the largest

I use formula method and factor method to solve 4x (2x + 1) = 3 (2x + 1)
Thank you

If we move the term, 4x (2x + 1) - 3 (2x + 1) = 0, (2x + 1) (4x-3) = 0, 2x + 1 = 0 or 4x-3 = 0, then x = 1 / 2, x = 3 / 4