What are the applications of functions?

Function is the specific solution of the analytic formula of the field and value, such as the sum function, it is the sum function, one of the most commonly used functions in excel functions, the sum function is the sum of the values of the range or cell, the application of each function is different in grammar, so it is impossible for anyone to completely apply all the functions to you, if you need to provide the region or value and what purpose or what result you want to write clearly, so that you can get specific help.

Are you satisfied with the above?

Because f(3xy) f(x) (fy), f(3) 1

So f(3)=f(3x1x1)=f(1)+f(1)=1 is equivalent to f(1)=1 2

So f(9)=f(3x3x1)=f(3)+f(1)=1+1 2=3 2

Hopefully.

1. Measure the height of a building or mountain.

If you know the location of the building with the elevation angle.

The distance between the buildings can be easily calculated.

2. Application in the game.

Some of the racing games we play use a lot of trigonometry.

When controlling the angle of the car, it is necessary to use trigonometric functions to calculate the current position of the car and the distance traveled.

3. Application in aviation flight.

Flight engineers must take into account their speed, distance and direction as well as wind speed and direction. Wind plays an important role in how and when an aircraft gets where it needs to be. For example, an airplane flies northeast at a speed of 1000 km h, and there is a southerly wind with a wind force of 200 km h.

Then it is necessary to use trigonometric functions to adjust the direction of the aircraft, so that it can fly in the right direction even if there is the influence of wind.

4. Application in criminal investigation.

In criminology, trigonometry can help calculate the trajectory of a projectile, estimate what might have caused a collision in a car accident, or how an object fell from a certain place and at which angle was a bullet shot, among other things.

5. Applications in astronomy.

In astronomy, trigonometric functions are often used to calculate the distance between the Earth and the stars.

Functional properties. Property 1: Symmetry.

Number line. Symmetry: The so-called number axis symmetry, that is, the function image.

Symmetry on the x and y axes of the coordinate axes.

Origin symmetry. Again, such symmetry means that the coordinates of the coordinates of the points on the function of the same origin on both sides of the origin are opposite to each other.

About point symmetry: This type is quite similar to origin symmetry, except that the symmetry point is no longer limited to the origin, but any point on the coordinate axis.

Nature 2: Periodicity.

Periodicity means that the image of a function in a part of the region is repeated, assuming that a function f(x) is a periodic function.

Then there exists a real number t, when the domain is defined.

When x is added to the beam or subtracted by an integer multiple of t, the y corresponding to x is unchanged, then it can be said that t is the period of the function, if the absolute value of t.

When the minimum is reached, it is called the minimum period.

Summary. Zero-point problems, application problems, and the comprehensive use of functions are often examined. Models for common function application problems: Function models at a time

Quadratic function model:; Power function model: (, is constant,); Exponential Function Model:

Logarithmic function model: (, is constant, ,).

It often examines the problem of zero scum, application problems, and the comprehensive application of functions. Models of common function application problems: Quadratic function model:;

Power function model: (, is constant,); Exponential Function Model:Logarithmic function model: (, is constant, ,).

Common ideas and methods for the application of functions and equations: 1. According to the topic, judge the type of function or equation applicable to the pose chain, whether it conforms to the exponential type or quadratic function type, etc. 2. Column equations according to the meaning of the topic and the actual interwheel parameters. 3. Solve practical application trace training.

How to write these 2 questions.

Thanks for the trouble.

There are a lot of questions, please be patient, and it will take time to type.

1. Fill in the blank question 1: If it can't be sold, y=0, there are 1000-2x=0, x=500

2: When x=100, 200, substitute y=, y=, 200, substitute y=, y=25

3：y=，x=10，ab=2x=20

2. Answer question: When you know u=ir, u=2, i=1, r=2, then there is u=2a

2, y=x*(20-2x), when x=5, y is up to 50

1) Set at the base of 20 yuan **x yuan, then sell 5x pieces less, from the title: y profit = (20 + 2x) (100-5x).

2) y=-10x+100x+2000, x=5, y=2250 maximum

The price increased by 10 yuan, and the sale was 2250 yuan, 75 pieces.

Sine function. A type of trigonometric function.

In the right triangle ABC, the angle C is equal to 90 degrees, AB is the hypotenuse, BC is the opposite side of angle A, and AC is the adjacent side of angle A.

The sinusoidal function is sin(a)=a h

Properties of sinusoidal functions:

Analytical: y=sinx

Image: Waveform image.

Define Domain: r-Range: [-1,1].

Maximum: Maximum: When x=(2)+2k, y(max)=1Minimum: When x=-(2)+2k, y(min)=-1 zero point: k, 0).

Symmetry: 1) Axis of Symmetry: Symmetry about the line x=(2)+k.

2) Central symmetry: Symmetry with respect to the point (k, 0).

Period: 2 Parity: Odd functions.

Monotonicity: on [-(2)+2k,(2)+2k] is an increasing function, and on [(2)+2k, (3 2)+2k] is a subtracting function.

The specific solution is that (1) let y=ax 2+bx+c, and then this function passes through the points (6,20),(7,,pre-pei(8,,, and brings it into the quadratic function to obtain a ternary system of equations, and then solves a=, b=, c=, so the relationship between y and x is y=,x> and Li stool = 6

2) Bringing x=12 into the relationship in (1) gives y=>9, so you don't have to declare bankruptcy!

If you don't understand anything, you can continue to ask questions!

1. Calculate the unit price of cost of sales: 300 x

2. The number of inventory responses decreased by 12: x-12

3. Sales revenue: 300 + 78 = 378 yuan.

4. Formula for calculating the number of sales bases:

Finch: x-12)*(300 x+1)=300+785, calculated result: 120.

Set each car each time to ride x people, (x is not greater than 55), then there are 5x people traveling every day, need to buy 5x cards, shout filial piety costs (5x*60) yuan, a total of (1500 Zheng Wuwen 5x) days, cost 5 * (1500 5x) * 500 yuan, so a total of caution needs to be spent.

5x*60+5*300/x*500=300*(x+2500/x)>=300*2*50=30000

If and only if x=50, the equal sign is true) (mean inequality) so each student needs to pay at least 30000 1500=20 yuan.