A question on mathematical modeling, urgent 100

Guo Dunwen: A netizen also asked this question, and I have already given it.

The form in which the workaround is given is as follows:

Project |Stock|Inventory Period|Consume feed|Feed Costs|Slaughter volume|Slaughter output value|Profit|

Boar|- Sow |——

Pigs|- Total|——

The upper workaround** form provides ideas for problem-solving modeling.

The more detailed modeling ideas for solving the problem are:

a) To conduct a survey to collect data, identify the following questions:

1) The proportion of boars and sows varies according to the breeding method, and the ratio of boars to sows is determined, such as 1:100;

2) determine the average weight of a single pig of ** pigs, e.g. 100 kg;

3) determine the amount of feed to be consumed in the production of 100kg pigs and **, the production cost of pigs is kg;

4) the number of days of the breeding pig's generation period, the average weight of the breeding pig, the amount of feed to be consumed and the production cost of the breeding pig kg.

ii) After the above data are determined, problems 1 and 2 can be solved.

3) Ideas for solving problem 3.

1) The best business strategy is to avoid the growth of pigs during the period when the price of pigs is low, so it is necessary to not breed or reduce mating during the period;

3) According to the results of (3, 2), the number of sows and pigs can be plotted.

The above is a modeling idea, which is a model (formula), and it cannot be a complete digital model.

Go to the post bar and take a look, maybe you will get something.

If the number of occupants in the committee is m, no n members can open it, and any n+1 committee member can open it, then the number of locks is c(m,n) (which means the number of combinations of n from m).

For this slide problem, c(11,5)=396 is what is sought.

Let the temperature of the object be t, and the rate of change of temperature is dt dt, where t is the time, and the temperature of the water is t1, then the temperature difference between the egg and the water is t-t1

From the meaning of the question: t-t1=kdt dt (where k is the proportionality constant) (1) equation (1) is reduced to : dt=kdt (t-t1) (2) to (2) both sides of the same integration and sorting out to get:

t=k*ln（t-t1）+c

Then the known data can be substituted to determine the coefficients k and c, here there is a hidden condition of the problem is that the temperature of the water has not changed t1 is always 18, and finally after determining k and c, you can find the time taken by the egg to 20, and then subtract 5 minutes to get how long it will take.

If you still don't understand, just ask privately.

1. Mathematical modeling: 1. Extract the mathematical model from the practical problem, 2. Solve the mathematical problem, 3. Then solve the mathematical problem, 4. Return to the practical problem, 5. Solve the practical problem. 2. Mathematics Application Problems 1. Application problems are just the simplest and most basic mathematical modeling. ：

What is a model for mathematical modeling? 1. When a mathematical structure is explained as a formal language (i.e., including a collection of symbols such as commonly used symbols, function symbols, and predicate symbols), the mathematical structure is called a mathematical model. 2. That is, the mathematical model can be described as:

For a specific object in the real world, for a specific purpose, according to the unique internal laws, make certain necessary assumptions, and then use appropriate mathematical tools to obtain a mathematical structure. 3. In this way, a mathematical structure, that is, a mathematical model, obtained on the basis of a certain abstraction and simplification, can help people to understand the object of study more deeply. 4. For example, the physics we study, especially the physics applied to engineering, such as circuits, theoretical mechanics, and material mechanics, is a good and intuitive example of mathematical modeling.

It's a bit of a hassle, 20 points is too little, at least 60 points.

Find someone you like, and you don't have a boyfriend, and you will definitely have a result for her. It depends on whether you are willing to pay first, to that extent, whether you have the attitude of not being able to do it, or a desperate love...

Answer: (1) B2+C2=A2+ 3BC

b^2+c^2-a^2=√3*bc.

cosa=(b^2+c^2-a^2)/2bc=√3/2,a=∏/6.

and sinasinb=cos 2(c 2), 1 2*[cos(a+b)-cos(a-b)]=(cosc+1) 2, Note: obtained by using the formula of product sum difference and cosc=2cos 2(c 2)-1, two formulas), there is.

cos(a-b)-cos(a+b)=cosc+1,cos(a-b)-cos(a+b)=-cos(a+b)+1,cos(a-b)=1,a-b=0, i.e., a=b=6,c=180-(a+b)=2 3.

2)√7/sin30=ab/sin(180-30-15)ab=2√7*sin45=√14.

Let , the triangle abc, the height on the edge of ab is h, h=tan30*14 2= 42 6

Area of ABC = 1 2 * ab * h = 7 3 6

Mathematical modeling is a general term that refers to the mathematical model, usually a formula, of a problem that is used to solve a similar problem. For example, e=mc 2 is a mathematical model of the relationship between the speed of light and mass. But mathematical models are not limited to formulas, and so on.

There should be a ready-made model for this topic, a multi-objective optimization problem.

Set the monthly production of a-x tons, b-y tons, the cost is.

Z1 = 2100x+4800Y, the profit is Z2 = 3600X+6500Y, and the capacity is limited to.

0<=x<=5,0<=y<=8,9<=x+y, if the capacity constraints are met, maximize z2 and minimize z1.

Since z1 should be small, -z1 should be large, so maximize z=z1*z2.