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Power function exponential function logarithmic function trigonometric function and inverse trigonometric function are collectively referred to as basic elementary functions. Can't you remember clearly
Right
Elementary function is a function generated by the combination of power function, exponential function, logarithmic function, elementary function, trigonometric function, inverse trigonometric function and constant through finite rational operation (addition, subtraction, multiplication, division, rational multiple power, rational multiple square) and finite function, and can be expressed by an analytical formula
It is the most commonly used type of function, including constant function, power function, exponential function, logarithmic function, trigonometric function, inverse trigonometric function (the above is the basic elementary function), and all functions obtained from these functions through finite four operations or function composition
Elementary function consists of power function, exponential function, logarithmic function, trigonometric function, inverse trigonometric function and constant through finite rational operation (addition, subtraction, multiplication, division, rational power and rational power) and functions of finite degree, which can be expressed analytically in the definition field Please give me a few functions formed by four finite operations. I can deepen my impression and make it easier to understand. Give me different examples In addition, under the interpretation, the power function, exponential function, logarithmic function, trigonometric function, inverse trigonometric function and constant undergo finite rational operations
This is very simple. You should understand it. For example, f (x) = 4x (SiNx + 3x) can be changed casually
Nanjing Yangtze River Bridge has a total length of 6700m. When a 200m long train passes through the bridge at a constant speed, it passes a distance of 600m in the first 40s. The time for all trains to pass through the bridge is______ s．
(1) Average train speed:
v=s
t=600m
40s=15m/s；
(2) Distance of the train passing the bridge:
S ′ = l Car + L bridge = 200m + 6700m = 6900m,
Time taken for the train to pass the bridge:
t′=s′
v=6900m
15m/s=460s．
So the answer is: 460
The lower railway of Nanjing Yangtze River Bridge is 6722 meters long, of which the main bridge on the river is 1572 meters long. It took 100 seconds for a 428 meter long train to completely pass the main bridge. Try to calculate how long it takes for this train to pass the railway bridge at a constant speed?
1. Train speed: = (1572 + 428) / 100 = 20m / S
2. How long does it take to completely cross the railway bridge: = (6722 + 428) / 20 = 357.5 seconds
The railway of the two stations is 628 kilometers long. The two trains of Party A and Party B leave from the two stations at the same time. Car a travels 72 kilometers per hour, and the speed of car B is six times that of car a Five. How many hours are the two cars still 100 kilometers apart?
Car a travels 72 kilometers per hour,
The speed of car B is 72 * 5 / 6 = 60
528/(72+60)=4
There are 7 stations on a passenger railway line. I want to prepare () kinds of tickets emergency
This is a statistical problem
That is, choose two of the seven stations to form a ticket
The formula listed in this way is C (7) (2) = 7 * 6 / 2 = 21
Where: C (7) (2) means that 7 is in the lower right corner of C and 2 is in the upper right corner of C
So if it's a one-way trip, you need to prepare 21 kinds of tickets
If it's a round trip, you need 21 * 2 = 42 tickets
According to the meaning of the title, it should be round-trip, so 42 kinds of tickets need to be prepared
Good luck!
RELATED INFORMATIONS
- 1. The railway between the two stations is 1464 kilometers long. Two trains leave from the two stations at the same time. It is known that the speed of one train is 63 kilometers and the speed of the other train is 59 kilometers per hour. How many kilometers did each line travel when they met?
- 2. A 200 meter long train passes through a tunnel at a speed of 4 meters per second for 240 seconds. How long is the tunnel? Calculation problem: a 200m long train passes through a tunnel at the speed of 4m / s for 240 seconds. How long is the tunnel? [write down the process as required
- 3. The Qing government appointed Zhan Tianyou as the chief engineer to build the railway from Beijing to Zhangjiakou!
- 4. When did Zhan Tianyou build the Beijing Zhangjiakou Railway
- 5. The railway passes near Qinglong bridge, and the slope is very large. How can the train climb such a steep slope? What rhetorical devices are used
- 6. A 200m long train passes through an iron bridge at a constant speed of V = 54km / h for 2min. Find the length of the iron bridge?
- 7. In triangle ABC, sin is known ² A+sin ² B+sin ² C = 2, then the triangle is? emergency
- 8. In △ ABC, the length of edges a and B is the two roots of equation x2-5x + 2 = 0, C = 60 °, find the length of edge C
- 9. In the obtuse triangle △ ABC, ∠ A is the obtuse angle ∠ B = 60 °, find the range of ∠ C
- 10. The diameter of the train wheel is 1.5 meters. The diameter of the train wheel is 1.5 meters. If the wheel rotates 300 cycles per minute, how many minutes does it take to travel 28.26 kilometers?
- 11. What is the second definition of ellipse, hyperbola and parabola?
- 12. On the sine theorem and cosine definite of triangle In triangle ABC, if sin2a = sin2b, what triangle must triangle ABC be? The answer is isosceles or right triangle!
- 13. Find indefinite integral ∫ [(e ^ (3x) - 1) / (e ^ (x) - 1)] DX How to get ∫ [(e ^ (x) - 1) (e ^ (2x) + e ^ (x) + 1) / (e ^ (x) - 1)] DX
- 14. If the maximum acceleration that passengers can endure in the subway train is 1.4m/s2. If the distance between two adjacent subway stations is 560m What is the shortest time for the subway train to travel between these two stations? The answer is 40,
- 15. A particle starts to move in a straight line with uniform acceleration from rest, and the acceleration is A1. After time t, it moves in a straight line with uniform deceleration, and the acceleration is A2. If it can just return to the starting point after time t, A1: A2 should be () A. 1：1 B. 1：2 C. 1：3 D. 1：4
- 16. An object starts to move in a straight line with uniform acceleration from rest. The acceleration is A1. The movement time is T1. Then it moves in a uniform deceleration with acceleration A2. After T2, the speed is exactly zero. Then the average speed of the object in the whole process can be expressed as? Why are 0.5a1t1 and 0.5a2t2 also right
- 17. A 200m long train passed the bridge. It was measured that it took 1 minute for the train to get off the bridge. The duration of the whole train on the bridge was 40s. Calculate the length of the bridge and the speed of the train
- 18. A train is 200 meters long and passes through a 1.8 km tunnel. It takes 2 minutes to calculate the train speed To be more detailed, there must be known, unit conversion,
- 19. Someone estimated the acceleration of the train with a watch. He observed it for 3min and found that the train had advanced 540M. After 2min, he observed it for 1min and found that the train had advanced 1620m If the train moves in a straight line with uniform acceleration within 6min, the speed of the train is? A.0.01m/s ² B.0.1m/s ² C.0.6m/s ² D.1.8m/s ²
- 20. Friction force F and sin α cos α Reference relation of equal trigonometric function That is, when to use sin when the inclination angle on the inclined plane has F α Or cos α For example, what does f = mgcosa mean, and what is the difference between uphill and downhill angles?