Four numbers, 3, - 5,7, - 13

Four numbers, 3, - 5,7, - 13

There are four algorithms for 24 point game title [3, - 5,7, - 13]
one
[7＋﹙-5×-13﹚]÷3
two
[﹙-5×-13﹚＋7]÷3
three
[7＋﹙-13×-5﹚]÷3
four
[﹙-13×-5﹚＋7]÷3
I do it for you by programming. It should be perfect,

Given TaNx = - 2, the value of sin ^ 2 * x + 3cos ^ 2 * x / 3sin ^ 2 * x - cos ^ 2 * x is?

Sin ^ 2 * x + 3cos ^ 2 * x / 3sin ^ 2 * x - cos ^ 2 * x divided by cos ^ 2 * x at the same time, then (Tan ^ 2 * x + 3) / (3tan ^ 2 * x-1)
Because TaNx = - 2, the original formula = (2 × 2 + 3) / (3 × 2 × 2-1) = 7 / 11

Fill in the circle with the appropriate arithmetic symbol and the box with the appropriate number
79 + 79 * 9 = Box * (box circle box).

Using the commutative law of addition 79 * 9 + 79

Is the image of a function defined on R continuous?

Not necessarily

The master and the apprentice process the same kind of parts. The apprentice processes 12 parts per hour. After working for 3 hours, the master starts to work. After 6 hours, they process the same number of parts. How many parts per hour does the master process?

12 × (3 + 6) △ 6, = 12 × 9 △ 6, = 12 △ 6 × 9, = 18 (pieces); answer: the master processes 18 parts per hour

The focus of the ellipse X29 + Y22 = 1 is F1 and F2, and the point P is on the ellipse. If | Pf1 | = 4, then | PF2|=______ The size of ∠ f1pf2 is______ ．

In △ f1pf2, cos ∠ f1pf2 = | Pf1 | 2 + | PF2 | 2 − | F1F2 | 22 | Pf1 | · | PF2 | = 16 + 4 − 282 × 4 × 2 = - 12, | f1pf2 = 120 degree

Grade 5 Volume 2 enjoy the summer vacation
1、 Read Pinyin and write words
Fragrance leisure beauty
Mao () son () lost ghost () Sheng
Make a scene
Wei an LAN Dao
2、 Fill in the blanks according to the text
1. People's social life always needs to learn to make the relationship between people and social life properly. Because being polite to others, you can, you can, you can
2. After learning the lesson of "love like jasmine", you must have a profound influence on love. Please write and share with us: ()

1： You: fragrant, leisurely and beautiful
Mao: hat, Daredevil, lush
Hu: butterfly, muddle headed, mischievous
Comfort, blue, taste
2： People always have to (communicate with others) in social life. Learning to (treat others politely) and properly (use polite language) can make the relationship between people (more harmonious) and social life (more beautiful). Because politeness can (build a bridge of understanding between people), can (resolve the contradiction between people), and can (solve the contradiction between people), Yes (social life is better)
After learning the lesson of "love like jasmine", you must have a profound influence on love. Please write about it and share it with us: (true love is as plain and fragrant as Jasmine)

If the equation of a circle is known as x ^ 2 + y ^ 2 + 8y = 0, then the linear equation of the longest chord and the shortest chord of the circle passing through the point (3,5) where the chord length? Is located?

The equation of circle is x ^ 2 + (y + 4) ^ 2 = 16
The coordinate of the point with people is greater than 16, so the point is outside the circle, the shortest chord length is 0 and tangent to the circle, and the equation is 3x + 5Y + 40 = 0
The largest is the line passing through the center of the circle and the point. The linear equation can be obtained by using the two-point formula

There are decimals in the practical problems of mathematics in Volume 2 of grade 4

1. 523 teachers and students take part in tree planting. If 70 people are divided into a group, how many groups can they be divided into at most
2. Use the computer to input a 466 word article. Honghong can input 60 words per minute, and Congcong can finish it in 7 minutes. Who can input faster
3. Uncle Wang's orchard harvested 358kg of apples, 270Kg of pears and 196kg of plums. Each box of apples is 40kg, each box of pears is 30kg and each box of plums is 20kg. How many cartons do you need to pack these fruits
4. Plant trees on the side of a 180 meter long road. Plant one tree every 20 meters. How many trees do you need to plant
5. Is 260 yuan enough for eight of us to buy tickets
6. The car travels 18 meters per second. The length of the car is 18 meters and the length of the tunnel is 324 meters. How long does it take for the car to pass through the tunnel
7. Chunguang grain and oil company wants to export 680 tons of grain. If 22 tons of containers are used, how many are needed? If 17 tons of containers are used, how many are needed
8. The highway from Shijiazhuang to Chengde is 546 kilometers long. When can the Honghong family drive from Shijiazhuang to Chengde to visit the summer resort? If they drive an average of 78 kilometers per hour and leave at 8 am, when can they get there
9. A rectangular vegetable field is 9 meters long and 6 meters wide. This vegetable field collects 972 kg of vegetables. How many kg of vegetables do you collect per square meter
10, the Oriental Pearl TV Tower in Shanghai is the tallest TV Tower in Asia. Its height is 468 meters. A building has 12 floors and a height of 39 meters. The height of the TV Tower is equivalent to the height of several 12 storey residential buildings.
11. The four cows raised by Wang Ye produce 896 kg of milk every week. How much milk does one cow produce every day
12. Four vehicles transport 960 bags of cement three times. How many bags of cement do each vehicle transport on average
(1) each classroom of Shuibo primary school has three windows, each of which is equipped with 12 pieces of glass. How many pieces of glass are installed in the nine classrooms
(2) There are 12 classrooms in Yangliu primary school. Each classroom has three windows. A total of 324 pieces of glass are installed. How many pieces of glass are installed in each window on average
14. Xiaohong bought two boxes of mung bean cake, weighing 1kg. Each box contains 20 pieces. How many grams does each piece weigh on average
15. A bus starts from Zhangcun. If it travels 60 kilometers per hour, it can reach Lizhuang in 4 hours. As a result, it only takes 3 hours to get there. How many kilometers does the bus actually travel per hour
16. Baita village plans to build a canal. If 16 meters are built every day, it can be finished in 18 days. The first day, 24 meters are built. According to the schedule of the first day, it can be finished in a few days
17. Hongguang Hotel bought 100 towels at 6 yuan each. How many towels can I buy if I use the money to buy a towel at 8 yuan
18. A pack of A4 copy paper, 25 sheets per day, just used up in 20 days. If less than 5 sheets per day, how many days can it take
19. A beekeeper keeps 24 boxes of bees this year. Last year, five boxes of bees brewed 375 kg of honey. According to the amount of honey brewed last year, how many kg of honey can be brewed this year
20. Dongdong family raised 135 seedlings on 15 square meters of land. According to this calculation, how much land is needed to raise 990 seedlings
21. Hongshi village primary school is divided into six groups to water trees. There are four people in each group. A total of 360 trees are watered. How many trees are watered per person on average
22. The number of eggs in a box is three times that in a basket. There are 96 eggs in a box and how many eggs in six baskets?
23. A train travels an average of 71 kilometers per hour before speeding up, 12 hours from Qinhuangdao to Handan, 95 kilometers per hour after speeding up, and about several hours from Qinhuangdao to Handan after speeding up
Aunt Wang is a skillful hand in making children's clothes. She can make 75 sets of children's clothes a week. Now she works five days a week. (1) how many sets can she make in 15 days
(2) How many days does it take to make 120 sets of children's clothes
25. A long-distance bus from Beijing to Qingdao passes through Tianjin and Jinan. It leaves Beijing at 6:30 in the morning, with an average of 85 kilometers per hour. When can it reach Qingdao
It is 137km from Beijing to Tianjin, 360km from Tianjin to Jinan and 393km from Jinan to Qingdao
26. Sunshine primary school has 960 teachers and students, sharing 60 tons in June. (1) how many tons of water does the school use every day
(2) According to this calculation, how many people can use one ton of water for one day and one month?
27125 male students and 119 female students are led by three teachers to visit the history museum. When visiting, they can only enter in batches, with a maximum of 50 students allowed each time
28. A story book has 448 pages. It takes Mingming 16 days to read it. Fangfang reads four more pages than Mingming every day. How many pages does Fangfang read every day
29. In order to carry out sports activities, the class takes the class fee to buy basketball and volleyball. It is known that it costs 161 yuan to buy three basketball and two volleyball. If it costs 245 yuan to buy three basketball and five volleyball, how much is a basketball and how much is a volleyball
30. Mingming is a studious child. He does some mental arithmetic every day except Sunday every week. If he does 300 mental arithmetic in a week, how many mental arithmetic can he do in three weeks
(2) 650 questions will be finished in a few days
31. A tit can eat about 800 pests in five days. According to this calculation, how many pests can a tit eat in a month? (a month is calculated as 30 days.)
32. A long bus can travel 174 kilometers in 3 hours. At this speed, how many kilometers can it travel in 12 hours?
33. Grandfather Zhang spent 75 yuan to buy three lambs. He wants to buy five more lambs. How much do he need to prepare?
34, 5 boxes of bees can brew 375 kg of honey a year. Xiaolin has 12 boxes of bees, how many kg of honey can be brewed a year?
35. A total of 180 young pioneers from Yuying primary school help their families do good deeds on the "love day". These young pioneers are divided into five teams on average, and each team is divided into four groups. How many young pioneers are there in each group on average?
36. Uncle Liu took 700 yuan to buy chemical fertilizer, bought 16 bags of chemical fertilizer, and left 60 yuan. What's the price of each bag of chemical fertilizer?
37. The eggs collected by Chunya chicken farm on Monday are 18 kg in a box. After 8 boxes are loaded, there are 16 kg left. How many kg of eggs were collected on Monday?
38. Uncle Wang drove from the county to Wangzhuang to deliver chemical fertilizer. When he went there, he traveled 40 kilometers per hour. It took three hours. When he returned, it took only two hours. How many kilometers per hour did he travel on average?
39. A tour bus travels for 2 hours in the plain and mountainous areas, and finally reaches the top of the mountain. It is known that the tour bus travels 50 kilometers per hour in the plain and 30 kilometers per hour in the mountainous areas. How long is the journey?
40. The school should add two new books to the library, three sets of each. It is known that the children's Encyclopedia is 125 yuan per set, and the mathematical guess is 18 yuan per set. How much will it cost altogether?
41. The school is going to send out exercise books to 15 classes, 144 in each class, and keep 40 as spare. How many exercise books should the school buy?
42. A sapling costs 16 yuan. Buy three saplings and get one free. How much is it cheaper to buy three saplings at a time?
43. Shampoo is 15 yuan per bottle. Shopping malls carry out promotional activities. Buy two bottles and get one free. How much is it cheaper to buy two bottles at a time?
44. A bunch of flowers is 20 yuan, buy 4 and get 1 free. Aunt Li buys 4 at a time, how much cheaper is each bunch?
45. Beijing Road Primary School plans to buy some desks and chairs. If you buy desks alone, you can buy 80 desks. If you buy chairs alone, you can buy 240 desks and chairs. How many sets of desks and chairs can you buy with this money?
46. Pour 3 cups of water into an empty bottle, which weighs 650 grams. If you pour 5 cups of water, which weighs 850 grams. If you pour 1 cup of water, how much does it weigh?

The area of a square is 10 square meters. How many meters is its perimeter

Let the side length be a, then
a^2=10
a=√10
So perimeter = 4A = 4 √ 10m