Given the set a = {x | - 1,1}, B = {x | - 2-2ax + B}, if B ≠ empty set and B contains a, find the value of a and B

Given the set a = {x | - 1,1}, B = {x | - 2-2ax + B}, if B ≠ empty set and B contains a, find the value of a and B

If B = {- 1}, then - 1 is the only solution of x ^ 2-2ax + B = 0, so the discriminant of quadratic equation (- 2A) ^ 2-4b = 0, a ^ 2 = B, and (- 1) ^ 2 + 2A + B = 0, 2A + B + 1 = 0, the solution of a ^ 2 = B, 2A + B + 1 = 0, the result is a = - 1, B = 1; for example

Let a = {- 1,1} B = {x | x ^ 2-2ax + B = 0}. If B ≠ an empty set and a contains B, find the value of a and B

A is contained in B, because B has at most two elements, so only b = a
Then the two of x ^ 2-2ax + B = 0 are - 1,1
According to Weida's theorem,
2a=-1+1=0
b=-1*1=-1
So a = 0, B = - 1

There are 240 students in Grade 6 of a school who are going to have a spring outing. There are two kinds of car rental schemes: the rental of 45 seat bus is 220 yuan, and that of 60 seat bus is 300 yuan. If you are in class, you can rent a car
If you are the monitor, how do you think to rent a car, the most economical? Please, urgent!

300 △ 60 = 5 yuan / person
220 △ 45 = 44 / 9 yuan / person;
5＞44/9
Therefore, try to rent 45 passenger cars, and make every car full
240＝45×4＋60×1
220 × 4 + 300 × 1 = 1180 yuan
So, hire 45 passenger car 4, 60 passenger car 1 most save money, need 1180 yuan

Known: 2 + 2 / 3 = 2 ^ 2x2 / 3, 3 + 3 / 8 = 3 ^ 2x3 / 8, 4 + 4 / 15 = 4 ^ 2x4 / 15, 5 + 5 / 24 = 5 ^ 2x5 / 24 If 10 + B / a = 10 ^ 2xb / A
In accordance with the previous formula, then a + B = ()

From 2 + 2 / 3 = 2 ^ 2x2 / 3, 3 + 3 / 8 = 3 ^ 2x3 / 8, 4 + 4 / 15 = 4 ^ 2x4 / 15, 5 + 5 / 24 = 5 ^ 2x5 / 24 So when n = 10, 10 + 10 / (10 ^ 2-1) = 10 ^ 2 * 10 / (10 ^ 2-1) B = 10 a = 10 ^ 2-1 = 99A + B = 109

What is the inverse matrix formula of square matrix?
A=1 2 3
2 2 1
3 4 3
I'll work out everything else
But why is a ^ * = M11 - M21 M31
-M12 M22 -M32
M13 -M23 M33
I have worked out the remainder formula M11 = 2, M12 = 3, M13 = 2 in my book
M21=-6.M22=-6,M23=-2
M31=-4,M32=-5,M33=-2
Then a * changes position a ^ * M11 - M21 M31 26 - 4
==== -M12 M22 -M32===== -3 -6 5
M13 -M23 M33 2 2 -2
I just can't understand that the remainder formula has been multiplied by (- 1) ^ m + N ~ how can I change the symbol below?
Is that the formula?

Yes, the inverse matrix of a = a * / A
And a * = (Aji) n × n = (- 1) j + imji
Man, take a good look at the textbook. Mji is called Aji's copula, which is not preceded by (- 1) j + I, and (Aji) is called Aji's algebraic copula, which is signed

Xiaobin travels for a week on holiday. If the sum of the days of the week is 84, the last day of the week will be 84______ No

Let the date of the fourth day be X. according to the meaning of the question, we get (x-3) + (X-2) + (x-1) + X + (x + 1) + (x + 2) + (x + 3) = 84. Then we get x = 12. Then x + 3 = 15, that is, the last day is the 15th. So we fill in 15

lim(x→0)(1+3tan^2(x))^cot^2(x)=?

In fact, this topic is two important limits: LIM (x →∞) (1 + 1 / x) ^ x = E. note that TaNx and Cotx are reciprocal, so LIM (x → 0) (1 + 3tan ^ 2 (x)) ^ cot ^ 2 (x) = LIM (x → 0) (1 + 3tan ^ 2 (x)) ^ [1 / Tan ^ 2 (x)] = LIM (x → 0) (1 + 3tan ^ 2 (x))

Let a = 2A + 3a-5, B = the square of 2A + 2a-5

There is a difference between B and a
B-A=2a^2-3a=a(2a-3)
Analysis: when B-A > 0, either a and 2a-3 are both positive or negative
A > 0 & a > 3 / 2, so a > 3 / 2
When both are negative, a

Well, what are you going to do

Well,what are you going to do?

How much is 100 yuan
100 yuan is 10000 cents

100 yuan is 10000 cents