A certain value in a function is y or X in the square of y equal to X

A certain value in a function is y or X in the square of y equal to X

No special explanation generally refers to x, according to the specific topic to analyze

Is the square of y equal to x a function of X

No

What is the square of a function y = x, y '

y=x^2
The first derivative of Y: y '= 2x

A and B leave from Nanjing and Beijing at the same time. Car a travels 70 kilometers per hour, while car B travels 80 kilometers per hour
What's the distance from Nanjing to Beijing

Two cars per hour: 70 + 80 = 150 km
Four hours of two cars: 150 * 4 = 600 km
In 4 hours, the distance between two vehicles is one third of the whole journey, and 1-1 / 3 = 2 / 3 of the whole journey
Let the whole process be X
X:1=600:2/3
X = 900 km

In triangle ABC, if a = x, B = 3x, a = 45 degrees, then the number of triangles satisfying this condition is

In sine theorem: A / (Sina) = B / (SINB)
And ∵ a = x, B = 3x, a = 45 degrees
The results show that SINB = (3 √ 2) / 2
The maximum value of ∵ sin is 1, and (3 √ 2) / 2 is greater than 1
A triangle without this condition

A and B start at 2:00 at the same time. A runs 90 kilometers at 3:20 and B runs 90 kilometers at 3:40. What's the speed ratio of a and B

1 hour 20 minutes = 4 / 3 hours
1 hour 40 minutes = 5 / 3 hours
The speed of car a is: 90 * 3 / 4 = 67.5
The speed of car B is: 90 * 3 / 5 = 54
The speed ratio of a and B is 5:4

3A's square C - [2Ab's square-2 (abc-3 / 2Ab's Square) + 3A's square C] - ABC, where a = - 1 / 2, B = 2, C = 3

The square C of 3A - [the square-2 of 2Ab (the square of abc-3 / 2Ab) + the square C of 3A] - ABC
=3a²c-(2ab²-2abc+3ab²+3a²c)-abc
=3a²c-(5ab²-2abc+3a²c)-abc
=3a²c-5ab²+2abc-3a²c-abc
=-5ab²-abc
=-5x(-1/2)x2²-(-1/2)x2x3
=-10+3
=-7

After Wang Hua gave Zhang Ming eight exercise books, they had the same number of exercise books. After Zhang Ming gave Wang Hua eight exercise books, Zhang Ming's exercise books were half of Wang Hua's. how many exercise books did Wang Hua have?

Let Wang Hua use the original x book and Zhang Ming use the original y book. From the title, we can see: X-8 = y + 8, Y-8 = (x + 8) / 2, from which we can get: x = 56, y = 40, Wang Hua used to have 56 books

The general solution of the equation y "+ 6y '+ 13 = 0 is

For the problem of differential equation in University, there is a lot of fuss in the building. In addition, y '= P, the original formula is p' + 6p = 13, p '= DP / DX,
The original formula is DP / DX + 6p = 13, and then the variables are separated and integrated left and right to find the function of P with respect to X,
And then I integrate, and I get y,
Another simple one is to let y = e of Rx degree, and the original equation is R ＾ 2 + 6R + 13 = 0,
There is no real solution, but complex solution

A school organizes students' spring outing. If it rents several 45 seat buses, there are 15 people without seats. If it rents the same number of 60 seat buses, there will be one more, and the rest of the buses are just full. It is known that the daily rent of 45 seat buses is 250 yuan for each bus, and the daily rent of 60 seat buses is 300 yuan. Which bus is more cost-effective and how many cars?

Let's rent x buses with 45 seats. According to the meaning of the question, we get: 45x + 15 = 60 (x-1), and the solution is: x = 5, so the rent of 45 seats should be 250 × (5 + 1) = 1500 (yuan), and the rent of 60 seats should be 300 × (5-1) = 1200 (yuan), so it's more cost-effective to rent 4 buses with 60 seats