Ask for a math experiment report in the first year of high school, hurry!

According to the priority, *is before +, so i*i will be calculated first, and then the result will be used to add the previous i, for example.

Assuming that the value of i is equal to 2, then the result of i+i*i is:

Calculate i*i first, which is 2*2, which is equal to 4

Then use i to add this value, which is 2+4

The last is equal to 6

Dear, let's search for greedy algorithms. It may help you.

You should go to the C forum and ask questions.

I can write an elevator program for you, according to your above system requirements, the simulation will not understand,

Dude: Give me a quilt, kneel and beg, mailbox.

Can you write me a program? >Thank you,

It has been sent to your mailbox, please pay attention to check.

These textbooks are all there, you should take a good look at the books yourself, these are some basic things, or do it yourself.

Chapter 1 Solving Triangles Sine Theorem Cosine Theorem Sine Theorem, Application of Cosine Theorem.

Chapter 2 Sequence Sequence Equal Difference Series Proportional Series.

Chapter 3 Inequalities Inequalities Unary Quadratic Inequalities Binary Inequalities and Simple Linear Programming Fundamental Inequalities Root number ab a+b 2 (a 0 b 0).

t=2pi(l/g)^(1/2)

Period = 2pi multiplied by the root number (cycloid length divided by gravitational acceleration).

t＊t=4π＊πl/g

t is the period, l is the pendulum length. g is the acceleration due to gravity.

It is related to the pendulum length and gravitational acceleration, which is directly proportional to the opening of the pendulum length, and inversely proportional to the opening square of gravitational acceleration.

Iron nails are easy to rust in humid environments, and iron nails are also easy to rust in the presence of air and water. If there is only water and no air, the iron nails will not rust, and the iron nails will not rust without water. Another important factor that causes iron rust is that if the surface of the iron product is not clean, the iron nail will rust.

One more little knowledge: after the iron rusts, the volume of the sticker will expand to 8 times the original size!

Rust occurs when iron oxidizes with moist air.

The cause of rust is mainly the action of electrochemical corrosion and air oxidation, pure metal or active metal is mainly due to the oxidation reaction between the metal surface and the oxygen in the air, and the metal oxide is formed on the metal surface, that is, rust. If the metal contains more impurities, these impurities will form a chemical galvanic battery with the metal, and electrochemical corrosion will occur, thereby oxidizing the metal to form metal oxides.

Some metals, such as alumina, can rust and produce a dense oxide film that prevents further oxidation. However, the thinning of the oxide film produced after the rusting of some metals accelerates the oxidation of the metal, such as rust.

2 nails and a half in the water rust the fastest.

Because the rust of iron requires two conditions: oxygen and water. 1. Nail in the air, only oxygen, no water; 3 nails completely immersed in water Only water without oxygen will not work. Only 2 and a half nails are placed in the water with both oxygen and water, so the fastest.

Attached: Experimental Plan:

Solve this problem with a contrasting approach. Use three kinds of iron nails to place in these three different places: one in the toilet (a damp place), one on the balcony (a dry place), and the other in a glass filled with water.

Observe every day whether the nails rust at the same rate in different places.

Experimental materials. Long nails (three, use long nails to observe rust), three cups (for placing nails), notebooks, pens, etc.

Procedure: Step 1: Number three nails, No. 1 into the toilet, No. 2 into the balcony, and No. 3 into a cup filled with water.

Step 2: Observe the rust of the nails in each environment and make a record.

Step 3: Write a good ** and make a report.

Experiment Log: No. 1, No. 2, No. 3.

One day Two days.

Three days ( write not rusty, slightly rusty, completely rusty).

Experimental results: the nails in the humid environment rust quickly, and they are completely rusted by the next day; The nails placed in a dry environment only rusted slightly on the third day, and when placed in water, they did not rust at all. Because nails cannot be kept in water all the time, it is best to keep them in a dry place rather than in a damp place.