Using spherical coordinates to calculate triple integral I = ∫∫∫ Z ^ 2dV, where the graph is composed of x ^ 2 + y ^ 2 + Z ^ 2

Using spherical coordinates to calculate triple integral I = ∫∫∫ Z ^ 2dV, where the graph is composed of x ^ 2 + y ^ 2 + Z ^ 2




Calculate the triple integral fffz ^ 2dxdydz, where is the space area bounded by the ellipsoid x ^ 2 / A ^ 2 + y ^ 2 / b ^ 2 + Z ^ 2 / C ^ 2 = 1,
What I want to know is how to integrate X and y


It can be solved by section method
The spatial region can be expressed as {(x, y, z) | x ^ 2 / A ^ 2 + y ^ 2 / b ^ 2



Can you help me understand the cubic integral? If the quadratic integral is volume, then the cubic integral is four-dimensional. I can't understand it. Which one do you choose


Mathematical dimension, generally speaking, is related to the number of variables,
The first integration space is a two-dimensional plane, the number of variables is 1, the variables can be changed on the horizontal axis of the coordinate axis, and the function value represents the ordinate, so the ordinate value can be obtained according to the change of the abscissa of the function. The second integration space is a three-dimensional solid, and there are two variables, which can be changed on the horizontal and vertical axis of the coordinate axis respectively, and the vertical coordinate Z value can be obtained according to the change of X and y, This is exactly the geometry in three dimensions. The cubic integral space is four-dimensional and has three variables. After that, we can't directly observe its geometry. Its variables are x, y, Z. and its function value represents an attribute, such as mass, pressure, etc. to find the mass of a three-dimensional object is to find the cubic integral of the density function of the geometry



It includes the use of percentage and ratio
About 35 questions each
For example, 1.3 billion, a relatively large number of applications


1. A dictionary is priced at 18 yuan and sold at a 20% discount, which is still 20% higher than the cost price. What is the cost price of this dictionary? 20% discount = 80% 18 × 80% = 14.4 yuan 14.4 ^ (1 + 20%) = 12 yuan. 2. The washing machine factory produced 7200 washing machines in the first quarter, 20% more than planned. How many washing machines are planned to be produced in the first quarter



Sixth grade mathematics calculation + application problem
Calculation questions:
(1) 6 / 2-13 / 26 / 9-2 / 3
(2) (0.75-3 / 16) × (2 / 9 + 1 / 3)
(3) [1 - (1 / 4 + 3 / 8)] 1 / 4
How high is the floor of Xiaoping's house? Xiaoping said: this building has 15 floors, and my family lives on the sixth floor
2. Uncle Li said: This paper is too long. It took 3 hours to input 1 / 3 of the total
At this rate, Uncle Li works for 8 hours, how many parts of this paper can he input? How many parts are left unfinished?
3. There are 240kg fruit candy in total, 1kg per 4 bags. Only 3 / 4 of them have been filled. How many bags have they filled?


2-6 / 13 △ 9 / 26-2 / 3 = 2-2 / 3-2 / 3 = 2 / 3 (0.75-3 / 16) x (2 / 9 + 1 / 3) = (3 / 4-3 / 16) x (2 / 9 + 3 / 9) = 9 / 16x5 / 9 = 5 / 16 [1 - (1 / 4 + 3 / 8)] / / 1 / 4 = (1-5 / 8) / / 1 / 4 = 3 / 242x (6-1) / 15 = 14, because the floor can only calculate the height of the fifth floor for 3 hours, then 1 / 3 △ 3 =



Volume problems in grade six
Six cuboids, 3cm long, 2cm wide and 1cm high, are used to make a big cuboid
There are different spelling methods, in which the largest surface area is, and the smallest surface area is. The volume of the large rectangle is compared with the sum of the original six cuboids


There are three different spelling methods, the largest surface area is 22, and the smallest surface area is 14. Compared with the volume sum of the original six cuboids, the volume of the large cuboid is the same as that of the small cuboid



Application of cuboid volume in Grade 6
1. A wood with a square cross section is 6.8 meters long. After sawing it into three cuboids, the surface area increases by 16 square meters?
2. A rectangular iron box with a square bottom. If you unfold its side, you will get a square with a side length of 8 decimeters. Calculate the volume of the iron box


1. A wood with a square cross section is 6.8 meters long. After sawing it into three cuboids, the surface area increases by 16 square meters



Practical problems of cylinder volume in Grade 6
1. A rectangular lead block with a length of 9cm, a width of 7cm and a height of 3cm and a cube lead block with an edge length of 5cm are cast into a cylinder. The diameter of the bottom surface of the cylinder is 20cm. What is the height of the cylinder?
2. A cuboid tank is 4 decimeters long, 3 decimeters wide and 2 decimeters high. It is full of diesel oil. Now pour the diesel oil into a cylinder with a diameter of 4 decimeters on the bottom. There is 3 / 5 space in the cylinder. Calculate the height of the cylinder


1. The height is: (9 × 7 × 3 + 5 × 5 × 5) △ 1 (CM)
2. Height of cylindrical oil drum: (4 × 3 × 2) / (2 × 2 × 3.14) / (1-3 / 5) ≈ 4.78 (CM)



An applied problem of finding the volume of a cylinder in the sixth grade of primary school
The surface area of a cylinder is 125.6 square centimeters, and the sum of its bottom diameter and height is 10 centimeters. What is the volume of the cylinder?
The result of the formula can not be counted


Let the radius of the bottom be r cm and the radius of the top be h cm
Then 2R + H = 10
2*3.14*R*R+2*3.14*R*H=125.6
The solutions are: R and H
Volume = 3.14 * r * r * h



Questions and answers about volume
A cuboid glass jar is 8 decimeters long, 4 decimeters high and 2.8 decimeters deep. If a square iron block with 4 decimeters edge length is put in, how many liters of water will overflow from the jar?


(water depth should be 2.5 decimeters?) iron volume = 4 × 4 × 4 = 64 (cubic decimeters) glass tank space = 8 × 6 × (3-2.5) = 24 (cubic decimeters) overflow water volume = iron volume - glass tank space = 64-24 = 40 (cubic decimeters) = 40 (liters). [answer] the water in the tank will overflow 40 liters