Make a sentence: happy

Make a sentence: happy

I'm glad to meet you

Use "land" to make a sentence. It's urgent for the simple preschool class

The seedlings are thriving in the fertile soil

Draw the largest circle in a square. If the area of the circle is 18.84 square centimeters, then the area of the square is () square centimeters

Circle area: square area = π (D / 2) &# 178;: D & # 178; = π: 4
Area of square = 18.84 × 4 △ 3.14 = 24 square centimeter

If we know that the square of a minus AXB equals 8, the square of ab-b equals minus four, then the square of a plus 2, the square of AB plus B equals seeking!

The meaning of the title is known
a^2 - ab = 8 (1)
ab - b^2 = -4 (2)
(1) The result of formula (2)
A ^ 2 - 2Ab + B ^ 2 = 12, that is, (a - b) ^ 2 = 12, the solution is A-B = 2 √ 3 (3)
(1) Formula + (2)
A ^ 2 - B ^ 2 = 4, i.e. (a + b) (a - b) = 4, substitute (3) to get
a + b = 4/(a-b) = 4/(2√3) =(2√3)/3
So a ^ 2 + 2Ab + B ^ 2 = (a + b) ^ 2 = [(2 √ 3) / 3] ^ 2 = 4 / 3

If the image of the function y = f (x) (x belongs to R) is symmetric with respect to the straight line x = A and x = B (B is greater than a), then is f (x) a periodic function

There is a round table. The diameter of the table top is 0.9 meters. We need to make a tablecloth and sew a circle of lace. What's the area of the tablecloth? How long is the lace?
Come on!

Lace: 0.9 * 3.14 = 2.826 (m)
Area: 0.9 / 2 = 0.45 (m)
0.45 * 0.45 * 3.14 = 0.02025 * 3.14 = 0.063585 (M2)

1. A 5-meter-long cylindrical timber is sawed into three columns. The surface area is increased by 24 decimeters. The volume of this timber is ()
2. Y = 3x, then x is proportional to y
3. A map, the distance between a and B is 3.5cm, the actual distance is 35km, the scale of this map is ()
4. The volume of a cuboid and a cone is 45 cubic decimeters, and the volume of a cone is ()
5. The original price of a commodity is 200 yuan, which is lower than the original price ()
6. X: y = 1.2
7. If 1 / 2 x = y, then x is proportional to y
8. If the floor area is fixed, the area of floor tiles is related to the number of tiles ()

1. The surface area is increased by 4 bottom areas, 24 / 4 = 6. The volume is 6 * 50 = 300 cubic decimeters
2. Positive proportion
3.1:1000000
4.1 / 3 * 45 = 15 cubic decimeter
5.200-200 * 0.85 = 30.30 yuan less
6. Big 20%
7. Positive proportion
8. In inverse proportion

Please revise the wrong sentence
I feel his seriousness, carefulness, peace and warmth from his comments
2. I read the revision of my composition carefully
We should develop our own advantages and achievements and make continuous progress
4. Under the teacher's education, he made clear his learning attitude

I'm sorry. It's hard to type the modified symbols, so I wrote the correct sentences directly
I can feel his earnest and careful attitude, peaceful and warm heart from his correction
I read Mr. Ye's revision of my composition carefully
We should carry forward our own advantages, improve our achievements and make continuous progress
4. Under the teacher's education, he corrected his learning attitude

It is known that Y1 = x ^ 2, y2 = x + x ^ 2, Y3 = e ^ x + x ^ 2 are the solutions of the equation (x-1) y '' - XY '+ y = - x ^ 2 + 2x-2, and the general solution of the equation is obtained
Can you give me some ideas

（x-1）y''-xy'+y=-x^2+2x-2
It's a nonhomogeneous equation
In general, the general solution of the corresponding second equation is obtained first
Secondly, the general solution of the equation plus the special solution of a non-homogeneous equation is the general solution of the equation
Y1 = x ^ 2, y2 = x + x ^ 2, Y3 = e ^ x + x ^ 2 are solutions of the equation (x-1) y '' - XY '+ y = - x ^ 2 + 2x-2
So y2-y1 = X
y3-y1=e^x
It is the two linearly independent solutions corresponding to the second equation (x-1) y '' - XY '+ y = 0
So the general solution of (x-1) y '' - XY '+ y = 0 is c1x + c2e ^ X
The general solution of (x-1) y '' - XY '+ y = - x ^ 2 + 2x-2 is
C1x+C2e^x+x^2
This problem depends on the solution of second order equation and non-homogeneous equation

10 m3 = () m2

The units are different. They can't be converted. One is the space unit (cubic meter) and the other is the plane unit (square meter)