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What is the geometric meaning of the standard equation of a circle?
The distance between point (x, y) and center (a, b) is r
Then √ (x-a) ^ 2 + (y-b) ^ 2 = R
Square can get (x-a) ^ 2 + (y-b) ^ 2 = R ^ 2
The geometric meaning is: a circle is a set of all points whose distance from a plane to a certain point is equal to a fixed length
What is the meaning of geometric standard layer and load standard layer in PKPM? How is the structural standard layer specified?
You should be talking about the concept in version 05: 1. Standard floor (that is, the standard floor in PMCAD): the floor with exactly the same structural plane can be input only once and assembled many times in the actual model of the whole building. 2. Load standard floor: in fact, only one group of floor with the same constant live load value can be input. After definition, it is also in the floor group
What's the meaning of a standard U-box in security? How much is a U-box?
The concept of "U" is a unit that represents the external size of a server. It is an abbreviation of "unit". The detailed size is determined by the American Electronic Industry Association (EIA), which is an industry group. The reason why we need to specify the size of a server is to keep the server in an appropriate size so that it can be placed on an iron or aluminum rack
Mathematics problem inequality application problem
If you rent several 48 seat buses, it will be full; if you rent 64 seat buses, you can use 64 seat buses, you can rent one less, and one bus is not full, but more than half. It is known that it is 250 yuan to rent 48 seat buses and 300 yuan to rent 64 seat buses. Which bus is more cost-effective?
64 seats
A vehicle with 64 seats is required
Then 64 (A-1) + 32
Find the area of the triangle formed by the two intersections and the origin of the straight line y = 1 / 3x + 2 and hyperbola x ^ 2 / 9-y ^ 2 / 4 = 1
1 / 3x-y + 2 = 0 triangle takes the line segment of two intersections as the bottom edge, the distance from the origin to the straight line is high = | 0-0 + 2 | / √ (1 / 9 + 1) = 6 / √ 10, substituting y = 1 / 3x + 2 into x ^ 2 / 9 - (x ^ 2 / 9 + 4x / 3 + 4) / 4 = 1x ^ 2 / 9-x ^ 2 / 36-x / 3-1 = 1x ^ 2 / 12-x / 3-2 = 0x ^ 2-4x-24 = 0x1 + x2 = 4, X1 * x2 = - 24 (x1-x2) ^ 2 = (x1 + X2
A symmetry axis equation of the graph of the function y = cos (2x + π 2) is ()
A. x=-π2B. x=-π4C. x=π8D. x=π
The equation of symmetry axis of this function is 2x + π 2 & nbsp; = k π (K ∈ z). When k = 0, x = & nbsp; − π 4
Complete the idioms and fill in the blanks
Rare
-The square of 2 + the third power of 3 * (- 1) - (- 4) * 5
=4-3+20
=21
If the square of inequality ax + BX + C > 0, the solution is: 1 / 3
-1/2
Translation of English reading tape in grade four of primary school
Experts 'identify' UFO after 'white light' from sky
A white light flashed across the sky, experts identified "UFO"
An unidentified flying object appeared over the airport of Shijiazhuang,Hebei,for more than half an hour on Monday night and then disappeared,said eyewitnesses,some of whom took pictures.
An unidentified flying object appeared at Shijiazhuang airport in Hebei Province. According to witnesses, it lasted half an hour on Monday night (white light), and photos were taken
The ellipsoid UFO gave off a strong white light about 8,000 meters above the airport."Its size was much bigger than any star," Zheng Fengbin,a policeman,who took its pictures with his cell phone,said.
"It's bigger than any star," said Zheng Fengbing, a police officer who took photos with his mobile phone
Studying his picture carefully,experts said the UFO was probably a "man-made object" like an airship.
After careful study of the photos, experts said that the UFO is likely to be "artificial", like a spaceship
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