Dad's bookshelf is full of all kinds of books?

Dad's bookshelf is full of all kinds of books?

Dad's bookshelf is full of all kinds of books
"Book" is a big concept, including all kinds of books
Dad's bookshelf is full of books

The work is popular
Come on, in ten minutes
Don't add anyone's work

Calligraphy works are warmly welcomed by young readers in China recently

Books become companions

Books have become my lifelong companions

Inverse function of y = LNX / X

Only monotone function has inverse function
You want to know if y = LNX / X has an inverse function
Let's see if it's a monotone function
Take the derivative to see if it is constant greater than zero or constant less than zero
The derivative of the function is y = (1-lnx) / x ^ 2
Obviously, the right side of this formula is in the definition field: X is greater than zero
Not always greater than or always less than zero
So the original function is not a monotone function in the whole domain
So there is no inverse function

Function FX = x ^ e to the - x power, seeking monotonicity and extremum

Convert to: e ^ ln (a)!

If a multivariate function is continuous, does its limit exist?

Continuous, the limit does not necessarily exist
Limit exists and must be continuous

How to prove that projection matrix must be diagonalizable?
Problems in matrix theory
Projection matrix is idempotent matrix, so how to prove that idempotent matrix can be diagonalized?

Let p ^ - 1 * a * P = J
P^-1*A^2*P=P^-1*A*P*P^-1*A*P=J^2
J is the Jordan Standard form of A
If J ^ 2 = J, then J must be a diagonal matrix

Have you any other questions? Tom runs faster than any other student
Have you any other questions?
Tom runs faster than any other student.
Any other is followed by singular or plural

Any other means any other person or thing within the same scope
Any other is followed by a singular noun

In p-abcd, the bottom surface ABCD is a square with side length a. E.F is a square with side length a PC.BD And PA is equal to P
In p-abcd, the bottom surface ABCD is a square with side length a. E.F is a square with side length a PC.BD The side pad is perpendicular to the bottom ABCD, and PA is equal to PD, which is equal to ad twice the root of 2
EF parallel plane pad; (2) verification: plane PCE vertical plane PCD

PA equals PD equals ad twice the root of 2
PA²+PD²=AD²
Therefore, APD = 90 degree
AP⊥PD
Connect AC
It is easy to prove that f is the midpoint of AC
And E is the midpoint of PC
PA ‖ ef
So EF ‖ planar pad
The second question PCE is not the same, please check whether the question is copied wrong

English translation
A mountain at the tip
The emperor of hearts
Wind direction

Sharp mountain
Heart Emperor
Wind-point