The surface area increases by 4 square meters after two cylinders are cut into 10 cm on one cylinder?

The surface area increases by 4 square meters after two cylinders are cut into 10 cm on one cylinder?

Volume = 4 / 2x0,01
=0,02 (M3)
This is a 10 cm thick round board. It's very difficult to cut it into two round boards

A rectangular timber is 5.2 meters long. If it is sawn 10 cm short, its volume will be reduced by 1000 cubic centimeters. What is the original volume of this timber
Use arithmetic

The volume is reduced by 1000 cm ^ 3 because the saw is shortened by 10 cm
So the bottom area is 100cm ^ 2
So the original volume is 520cm * 100cm = 52000cm ^ 3
Because 1dm ^ 3 = 1000cm ^ 3
So the original volume is 52dm ^ 3
DM is decimeter
DM ^ 3 is the cubic decimeter

How is 2.8.8.8 equal to 24

(2+8/8)*8=24
2*(8+8)-8=24
8*8/2-8=24

Given that the sequence xn converges and xn = 1 + xn / xn + 1, where X1 = 1, then Lim n tends to be infinite xn =

Let xn converge to a
Then the limit of XN = 1 + xn / xn + 1 is as follows:
a=(1+a)/a
The solution is a = (1 ± 5 ^ 0.5) / 2
Because x (n + 1) = 1 + 1 / xn and X1 = 1 > 1
So any xn > 0
So a = (1-5 ^ 0.5) / 2 (∞) = (1 + 5 ^ 0.5) / 2

The side length of the first square is twice as long as that of the second one. The circumference difference between them is 44 cm. What are the side lengths of the two squares

Let the side length of the first square be x and the side length of the second square be 2x
4 times 2x minus 4 times x equals 44
4*2x-4*x=44
8x-4x=44
4x=44
x=11
2x=11*2=22
A: the side length of the first square is 11 cm, and the side length of the second square is 22 cm

How to simplify 3 / 0.75

3 / 0.75 = 3 △ 0.75 = 4

Known x1, X2 Xn are all positive numbers, proving: x2 / √ X1 + X3 / √ x2 + x1/√xn≥√x1+√x2 + …… √xn
1、2、3…… N is subscript

x2/√x1+√x1 ≥2√x2
x3/√x2+√x2 ≥2√x3
.
x1/√xn+√xn ≥2√x1
Add all to get:
（x2/√x1+x3/√x2+…… x1/√xn)+√x1+√x2 + …… √xn)≥2(√x1+√x2 + …… √xn)
So: x2 / √ X1 + X3 / √ x2 + x1/√xn≥√x1+√x2 + …… √xn
Take the equal sign if and only if X1 = x2 =... = xn

Mingmingjia's kitchen is 3 meters long, 2.6 meters wide and 3 meters high. I want to re tile the kitchen until 1.6 meters. The area of doors and windows below 1.6 meters is 2 square meters,
Ceramic tile is a square with side length of 20 cm. How many ceramic tiles do you need?
(the formula and the process should not be given directly.)

1.6*2.6*3/2

Definition of Kirchhoff's voltage law?

Kirchhoff's law is a law which clarifies the constraint relationship between the current flowing into and out of the node and the voltage along the circuit in lumped parameter circuit. It was proposed by German physicist g.r.kirchhoff in 1845. Lumped parameter circuit means that the maximum linear size of the circuit itself is far less than the current in the circuit

The domain of arcsinx / 5 + arcsinx / 5

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