∫ (e ^ 3x + 1) / (e ^ x + 1) DX = what,

∫ (e ^ 3x + 1) / (e ^ x + 1) DX = what,

E ^ 3x + 1 = (e ^ x + 1) (e ^ 2x-e ^ x + 1) after eliminating e ^ x + 1, there are three terms left. The indefinite integral of e ^ 2x is 1 / 2 * e ^ 2x. (omit the constant term and write together later) - the indefinite integral of e ^ x is - e ^ x1, and the indefinite integral of e ^ X1 is X

4 (x-6.2) = 20.8 with equation!

x-6.2=20.8/4=5.2
x=6.2+5.2
=11.4

The eccentricity of an ellipse whose center is at the origin and whose focus is on the coordinate axis is known to pass through the points m (1,423), n (- 322,2)
It is known that the ellipse with the center at the origin and the focus on the coordinate axis passes through the points m (1,42,3), n (- 32,2,2),
(1) Find the eccentricity of ellipse;
(2) Is there a point P (x, y) to a fixed point a (a, 0) (where 0) on the ellipse

I don't know if your number is correct. If it is correct, the amount of calculation is too large

Solve the equation. [x + X + 15] * 3 = 360

【X+X+15】*3=360
2X+15=360/3
2X+15=120
2X=120-15
2X=105
X=105/2
X=52.5

Why is cos-4 π / 3 equal to - 1 / 2

One method is to draw a picture, and the other is y = cosx. This function is even function, so cos-4 π / 3 = Cos4 π / 3 = cos (π + 1 π / 3) = - cos1 π / 3 = - 1 / 2

Divide 45 by the reciprocal of 7 / 9, and the quotient is 15 more than a number. Solve the equation

Let this number be X
45÷9/7=x+15
x+15=35
x=35-15
x=20

Fill the eight integers 1-8 in the following brackets to make the equation true: (& nbsp;) (& nbsp;) = 9 () () = () () ()

36＝918＝2754．

Help solve an equation, x-18 = 3 (x-26)

x-18=3(x-26)
x-18=3x-3*26
x-18=3x-78
3x-x=78-18
2x=60
x=30

How about these,
2^x＋x＝0
log2 x ＋x＝0
Please, gods, what's the calculation?

(1)2^x + x =0
The derivation of the two sides is as follows
2^x*ln2 +1 =0;
2^x=-1/ln2
Take log2 on both sides,
x=log2(-1/ln2)
（2）log2(x)+x =0
The derivation on both sides is obtained,
1/x*1/ln2+1=0
That is 1 / (xln2) + 1 = 0
So x = - 1 / LN2
I hope my answer can help you. I wish you progress in your study. If you have any questions, please feel free to ask

For primary school fifth grade last semester equation application questions 100, an unknown number, urgent

1. The two trains leave from the two places at the same time. Car a runs 62 kilometers per hour, and car B runs 70 kilometers per hour. After hours, they meet. How long is the railway between the two places?
2. Two machines produce the same kind of parts. The first machine produces 20 parts per hour, and the second machine produces 80 parts per hour. How many hours does it take for two machines to produce 98 parts at the same time?
3. A suit is 160 yuan, of which the price of trousers is that of top. How much are the prices of top and trousers?
4. The typist typed a manuscript. He typed 12 pages on the first day and 13 pages on the second day. The number of pages typed in these two days accounts for the majority of the manuscript. How many pages is the manuscript?
5. The pictures on the matchboxes collected by Xiaohua are 60 more than those collected by Xiaoming. The pictures on the matchboxes collected by Xiaoming are Xiaohua's. how many are the pictures on the matchboxes collected by Xiaohua and Xiaoming?
6. (1) a construction site uses 18 tons of cement in the first half of September, and the cement used in the second half of September is the same. How many tons of cement are used in September?
(2) A construction site uses 34 tons of cement in September, of which the cement used in the second half of the month is that in the first half. How many tons of cement are used in the first half of the month?
7. An engineering team built a highway. It was 38 meters in the first day and 42 meters in the second day. The second day, more than the first day, was the total length of the road. How many meters is the total length of the road?
8. A desk is 10 yuan more expensive than a chair. If the unit price of a chair is that of a desk, how many yuan are the unit prices of the desk and chair?
9. There is a batch of coal in the port. First, it is transported by 8 large trucks, each of which is loaded with 5 tons; the rest is transported by 5 small trucks, each of which is loaded by a large truck, which is just finished at one time. How many tons of coal are there in total?
10. In order to celebrate the school anniversary, class three of the fifth year will make 180 small flags. They have already been made. How many more have not been made?
11. To make a kind of machine tool, it used to use 2 tons of steel for each machine tool, but now the steel used for each machine tool is less than the original. How many tons of steel are used for each machine tool now?
12. (1) there are 1200 ducks in a farm. There are more chickens than ducks. How many more chickens are there than ducks?
(2) There are 1200 ducks in a farm. There are more chickens than ducks. How many chickens are there?
13. (1) a rope is 2 meters long, minus, how many meters are left?
(2) A rope is 2 meters long. How many meters are left after subtracting meters?
14. Li Xiaohong read an 80 page story book. On the first day, she read the whole book. On the second day, she read the whole book. How many pages are left?
15. One kind of clothing original 105 yuan, now reduces the price, the present price is how many yuan?
16. A soap factory produced 350000 cases of soap in September, and more soap was produced in October than in September. How many cases of soap were produced in October?
17. The students took part in the work of transporting bricks. A total of 1500 pieces were transported in two days. The first day, how many pieces were transported in the second day?
18. A car factory planned to produce 12600 cars last year. As a result, it completed the annual plan in the first half of the year, and completed the annual plan in the second half of the year. How many cars were overproduced last year?
19. The part buried in the ground is full-length, and the part exposed to the ground is 5 meters. How many meters is the total length of this pole?
20. (1) an artificial earth satellite runs 8 kilometers per second, which is equivalent to that of a spaceship. How many kilometers does the spaceship run per second?
(2) Artificial earth satellite runs 8 kilometers per second, which is slower than spaceship. How many kilometers per second does spaceship run?
21. (1) the total output of green vegetables in a county last year was 7.2 million kg, which is the largest of the total output of green vegetables this year?
(2) The total output of green vegetables in a county last year was 7.2 million kg, which is higher than that of last year. How many million kg is the total output of green vegetables in the county this year?
22. The number of beef cattle sold in a livestock farm is 250. How many beef cattle are there in this livestock farm?
23. A county planted 1260 hectares last year, exceeding the original plan. How many hectares was the original plan?
24. The tallest animal in the world is giraffe. There is a giraffe which is 5 meters tall, higher than an elephant. How many meters is this elephant tall?
25. The area of a square is 20 square meters. After renovation, the area has increased. How many square meters is the area of this square?
26. Dolphins can swim 70 kilometers per hour, faster than blue whales. How many kilometers can blue whales swim per hour?
27. The weight of silver per cubic centimeter is gram, which is lighter than that of lead per cubic centimeter?
28. Analyze the quantitative relationship of the following questions, and list the formula or equation (without calculation)
(1) There are 60 willows in the campus. There are more poplars than willows. How many are there?
(2) There are 60 willows on campus, less than poplar. How many poplar trees are there?
(3) There are more poplars than willows on campus. There are 75 poplars and how many willows?
(4) There are fewer willows than poplars on campus. There are 75 poplar trees. How many willows are there?
29. (1) there are two bundles of wires. One bundle is 120 meters long, shorter than the other bundle. How long is the other bundle of wires?
(2) There are two bundles of wires. One bundle is 120 meters long, which is longer than the other bundle. How long is the other bundle of wires?
(1) the original price of a VCD player was 1260 yuan. Now the price is lower than the original price. How much is the current price?
(2) A VCD player now costs 924 yuan. Now it's cheaper than before. How much is the original price?
There are 15 pear trees and 20 apple trees in the school orchard
(1) How many more apple trees than pear trees?
(2) How many fewer pear trees than apple trees?
(3) How many more apple trees than pear trees?
(4) How many pear trees are less than apple trees?
How many kilos of pears does the store bring?
33. Xiaojun's model plane flew in the air for 2 minutes, which was longer than Xiaofeng's model plane. How long did Xiaofeng's model plane fly in the air?
34. 550Kg flour was transported from the store, and less rice than flour?
35. (1) the highway between a and B is 216 kilometers long. How many kilometers is there for a car from a to B?
(2) A car from a to B, the whole line, just 81 kilometers. How long is the highway between the two places?
(3) A car from a to B, the whole line, there are 135 kilometers from B. how long is the highway between the two places?
(4) A car from a to B, the first hour of the whole line, the second hour of the whole line, two hours of 114 kilometers. How long is the road between the two places?
36. There are two steel pipes of the same length. The first one is for rice, and the second one is for rice. Which one is longer?
37. To process a batch of parts, Party A shall do it alone for 6 hours and Party B shall do it alone for 9 hours
(1) How many parts per hour does a complete this batch of parts? How many parts per hour does B complete this batch of parts?
(2) How many parts of this batch of parts can be completed per hour?
(3) How many hours can we finish the task if Party A and Party B work together?
38. Processing a batch of parts by one person takes 12 hours for Party A, 10 hours for Party B and 15 hours for Party C
(1) If a and C work together, how many hours can they complete it?
(2) If B and C work together, how many hours can they complete it?
(3) If a, B and C work together, how many hours can they complete it?
39. A pile of goods can be transported in 4 hours by car a alone; B can be transported in 6 hours by car B alone. Now how many hours does it take to transport this pile of goods by car a and B together?
40. (1) two trains depart from two cities 660 kilometers apart at the same time. One train travels 60 kilometers per hour, and the other 75 kilometers per hour. How many hours can two trains meet?
(2) Two trains leave from city a and city B at the same time. It takes 10 hours for one train to leave from city a to city B, and it takes 8 hours for the other train to leave from city B to city A. how many hours can the two trains meet?
41. It takes five hours for Zhang Hong to copy a manuscript. This manuscript has been copied by others, and the rest is handed over to Zhang Hong. How many hours will it take to finish it?
42. The school has bought a batch of new books, including 30 story books and 18 science and technology books, accounting for the total number of these books. How many of these new books are there?
(1) the waterway from Shanghai to Hankou is 1125 kilometers long. A ship has already gone from Shanghai to Hankou. How many kilometers are there from Hankou?
(2) A ship from Shanghai to Hankou has already gone. It is 450 kilometers away from Hankou. How many kilometers is the waterway from Shanghai to Hankou? (what are the similarities and differences between question 1 and question 2? Which quantity should be regarded as unit "1"? Is the calculation method the same?)
(1) there are 18 buses in the parking lot. There are more cars than buses. How many cars are there?
(2) There are 18 buses in the parking lot. The number of buses is less than that of cars. How many cars are there?
(3) There are 21 cars in the parking lot. There are fewer buses than cars. How many buses are there?
(4) There are 21 cars in the parking lot. There are more cars than buses. How many buses are there? (what are the similarities and differences between question 1 and question 2? Who do they regard as unit "1"? What are the similarities and differences between question 3 and question 4? Who do they regard as unit "1"?)
(1) the distance between port a and port B is 312 km