Postgraduate entrance examination number one is required to understand the second-order Taylor formula of binary function, so what degree do we need to understand? What kind of questions will be given?

Postgraduate entrance examination number one is required to understand the second-order Taylor formula of binary function, so what degree do we need to understand? What kind of questions will be given?

Second order Taylor formula does not need a deep understanding, basically can't test, I from 97 to 11 years of real problem, basically didn't appear second order Taylor's problem. But a section of Taylor formula but must master, is the key! Many proof problems in you can't think of a method, expand Taylor public will have unexpected effect

Which functions can be expressed by Taylor formula?

In mathematics, Taylor's formula is a formula that uses the information of a function at a certain point to describe its value nearby. If, for example, the exponential function ex is near x = 0, it can be approximately expressed by the following Polynomials: where

English translation
call out
call for

Call out
Call for

Triangle ABC is an inscribed triangle with circle P: (X-2) ^ 2 + y ^ 2 = 8, and the coordinates of its center of gravity g are (1,1). The equation for finding straight line BC is given
A(0,-2)

Let B (x1, Y1), C (X2, Y2), then, X1 + x2 = 3, Y1 + y2 = 5. Substituting into the circle equation: (x1-2) ^ 2 + Y1 ^ 2 = 8, (x2-2) ^ 2 + Y2 ^ 2 = 8, we can get (y1-y2) / (x1-x2) = 1 / 5, that is, BC slope K1 = 1 / 5. Let the midpoint of BC be D and the center of circle be p, then PD slope K2 = -

Phrases related to out
A little more, er, the most important thing is the phrase with out that means "block.",

There is no such question
Dizzy. Give you a few better, and then with an example
prevent out
Nothing can prevent us from carrying out the plan
block in
The jeep has been blocked in by all those lorries.
clog with
i want to clog the hole with a stopper.
inpede in
He was impeded in his work.
Please. I think so much And they are all right!
Don't you think I should get the points?
And the last one, I specially went to the Internet to check if I remember correctly

The fraction whose numerator and denominator are two adjacent nonzero natural numbers must be the simplest fraction

Yes
If a number contains a factor a which is not equal to 1, then another number must be larger or smaller than this number in order to also contain factor A. but the numerator and denominator are adjacent non-zero natural numbers, and one of them is only 1 larger or 1 smaller than the other number, so it is impossible to have other common factors other than 1, that is, the numerator denominator is coprime, so it is the simplest fraction

The field of (adjectives and words)
You have to have 10 adjectives to get full marks

Fields of hope
Vibrant fields
Green fields
Endless fields
Beauty Field
Barren fields
Fields in the twilight
Snow covered fields
Fields with green grass
Vast fields

What is the simplification of radical 26

It's the root 26, because 26 is a prime

How to use English verb phrases alone?
I want to use a phrase to express my state. Should the verb in the phrase use the original form or gerund?
For example, reading in silence or reading in silence?

In fact, both can, generally there is no strict limit
The verb prototype emphasizes action; the gerund form emphasizes state

It is known that ad ⊥ BC, eg ⊥ BC, ∠ e = ∠ AFE

∫ eg ⊥ BC, ad ⊥ BC, ∪ EF ∥ ad, ∪ 1 = ∨ 2, ∨ 3 = ∨ e, ∨ e = ∨ 1, ∨ 2 = ∨ 3. ∨ ad bisection ∨ BAC