![](data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 72 71" width="72"></svg>)
There is a column of numbers arranged from small to large, the minimum number is - 3, and then each number is 2 larger than the previous number, and the maximum number is 155. Note that the nth number is y, and find the analytic expression of Y function on N and the value range of independent variable n. how many numbers are there in this column? (to be specific)
The first number is - 3 = - 3 + 2 * 0, the second one is - 1 = - 3 + 2 * 1, and the third one is 1 = - 3 + 2 * 2, so the nth number is y = - 3 + 2 * (n-1). Because - 3 ≤ y ≤ 155 - 3 ≤ - 3 + 2 * (n-1) ≤ 155, the number of integers in the range [1,80] of 1 ≤ n ≤ 80 is obtained
A fruit sales company in our city needs to transport a batch of fresh peaches produced in Xiaogan Yangdian to a certain place. There are cars and trains to choose from. One is car: average speed on the way (unit: km / h): 75 average cost on the way (yuan / km): 8 loading and unloading time (hours): 2 loading and unloading cost (yuan): 1000; the other is train: average speed on the way: 100 average cost on the way: 6 Loading and unloading time: 4. Loading and unloading cost: 2000. If the loss of this batch of fruits during transportation (including loading and unloading time) is 150 yuan / hour, which means of transportation do you think is better (that is, the sum of transportation cost and loss is less)?
The title is as above, we should seize the time to solve it, we must hand in the homework tomorrow, the process must be clear, detailed and complete, we must discuss it in several steps, we must write it clearly, wait, thank you``
Set the distance from the starting point to the end point as X km
(1) Cost of using the car:
y=（x/75+2）*150+8x+1000
=10x+1300
(2) The cost of using the train
z=（x/100+4）*150+6x+2000
=7.5x+2600
Let y = Z be the solution
x=520
So when x = 520, the train cost is smaller
[function problems in the second year of junior high school,
There are 12 and 6 machine tools stored in city a and city B respectively. Now there are 10 machine tools to be transported to City C and 8 machine tools to be transported to city D. if one machine tool is transported from city a to City C and city D, the freight will be 40000 yuan and 80000 yuan respectively. If one machine tool is transported from city B to City C and city D, the freight will be 30000 yuan and 50000 yuan respectively,
1. Let B city be transported to x station in C City, and find the functional relation between the total cost y (ten thousand yuan) and X and its definition field
2, if the total cost is not more than 950 thousand yuan, there is a centralized dispatching method.
3. How many ten thousand yuan is the lowest total cost?
1. Y = 3x + 5 (6-x) + 4 (10-x) + 8 (12 - (10-x)) = 2x + 86 (domain 0
Mathematical function problems in grade two of junior high school
If a (x1, x2) and B (X2, Y2) are two different points on the image of a linear function y = 3x-1, and X1 &; x2 ≠ 0, let m = (Y2 + 1) / x1, n = (Y2 + 1) / X2, then the size relation of M and N is ()
A.M＞N B.M＝N
C. M ＜ n D. cannot be determined
Give the process of solving the problem
Er Er, wrong number, M = (Y1 + 1) / x1
y1=3x1-1 y2=3x2-1
M=(3X1-1+1)/X1=3
N=(3X2-1+1)/X2=3
So m = n
Choose B
The function problem of grade two in junior high school,
In the plane rectangular coordinate system, point O is the origin of the coordinate. We know that the isosceles trapezoid oabc, OA / / BC, point a (4,0), BC = 2, the height of the isosceles trapezoid oabc is 1, and points B and C are in the first quadrant
(1) Please draw a plane rectangular coordinate system and draw isosceles trapezoid oabc in this coordinate system
(2) The intersection of line y = - 1 / 5 + 6 / 5 and line AB and point P (P, q), point m (m, n) is on the line y = - 1 / 5 times x + 6 / 5, when n > Q, the value range of M is obtained
1) According to the conditions, OA is the bottom, BC is the top, OA is on the positive half axis of X, BC is in the first quadrant, if the height is 1, then the ordinate value of B and C is 1. If this trapezoid is isosceles trapezoid, then according to the symmetry characteristics of isosceles trapezoid, we can know that the abscissa of B is 3, and the abscissa of C is 1, so isosceles trapezoid
As shown in the figure, it is known that two lines L1 and L2 intersect at point a (4, 3), and OA = ob, please find out the corresponding function analytic expressions of the two lines respectively
Let L1 be y = K1X, 4k1 = 3, K1 = 34, that is, L1 is y = 34x (3 points) ∵ a (4, 3) ∵ OA = 5 = ob ∵ B (0, - 5) (5 points) let L2 be y = k2x + B. then there are: 4k2 + B = 3B = − 5, ∵ K2 = 2, that is, L2 is y = 2x-5 (8 points)
The analytical expression of the line obtained by translating the line y = 2x upward by 2 units is______ ．
The analytic formula of the straight line is y = 2x + 2 after the straight line y = 2x moves up 2 units. So the answer is y = 2x + 2
The monthly gas consumption of a household is 72 cubic meters (within the base), and it needs to pay 75.60 yuan. For any household in the area, the monthly gas consumption within the technology is x (cubic meters), and the consumption amount is y (yuan). Find the function analytical formula of Y (yuan) with respect to X (cubic meters)
Y=（75.60/72）X
1. A train is traveling at a speed of 90 km / h at a constant speed, and the analytic function of the variation of its travel distance s (unit: km) with the travel time t (unit: H) is obtained
2. The length of a spring is 12cm when it does not hang a heavy object. The length of the spring after hanging a heavy object is proportional to the mass of the hanging object. If the spring after hanging a 1 kg object is extended by 2cm, the analytic function of the total length of the spring y (unit: cm) changing with the mass of the hanging object x (unit: kg) is obtained
S=90t
y=12+2X
Urgently seek, and an analytic expression of elementary two functions
If the images of the positive scale function and the first-order function pass through the point m (5,4), and the area between the images of the positive scale function and the first-order function and the Y axis is equal to 17 / 2, the analytic expressions of the two functions are obtained
Let the positive proportional function be y = KX and the primary function be y = ax + B
The image passes through point m (5,4), and two functions are brought in
4 = 5K, that is k = 4 / 5
4=5A+B
The intersection point of the linear function y = ax + B and Y axis is (0, b), the height of the enclosed triangle is 5, and the bottom edge is B
Then: 5 * B / 2 = 17 / 2, B = 17 / 5
Then a = 3 / 25
RELATED INFORMATIONS
- 1. The function f (x) = 3 ^ (2x) - (K + 1) * 3 ^ x + 2, when f (x) is always greater than zero, the value range of K is obtained One is the method of quadratic function, more troublesome, there is another method, forget what the principle is, please help Why is Δ wrong? 2√2-1）
- 2. The definition of the function is For any domain x, there is a unique y corresponding to it For multivalued functions, X and y are not unique, which is not in contradiction with the definition of function Even if we divide multi valued functions into single valued functions, what makes sense is single valued functions. Does multi valued functions make sense? This is a problem that I can't understand all the time, because I don't like high mathematics, Thanks for the answer from the first floor, but can this answer explain the trajectory equation of a circle? For example, is the trajectory equation of the unit circle not a function? Because there's x for two Y's On the contrary, one y corresponds to two X!
- 3. The period of the function y = 1 + cos4x, X ∈ R is______ The even function of
- 4. If y = sinwx (W > 0) has two maximum values in [0.1], the period of function is calculated
- 5. It is known that f (x) = 2cos ^ 2x + 2 √ 3xinxcosx + a (x ∈ R) a is a constant (1) Finding the minimum positive period of F (x) (2) Finding monotone increasing interval of F (x) (3) If the sum of the maximum and minimum of F (x) is 3, find the value of A
- 6. Ask a few mathematical function questions Y = the range of the root sign (xsquare - x + 2) The minimum value of y = x square + 2x + 2 The maximum value of y = 2 - | x |
- 7. Mathematical function problem? 1. A factory produces one kind of parts, and the daily income is 28 yuan when the quota is fulfilled. If one part is overproduced and the income is increased by 1.5 yuan, then the functional relationship between a worker's daily income y yuan and the number of overproduced parts x is () 2. A factory has 800 tons of coal and burns 5 tons of coal every day. Find out the functional relationship between Y tons of surplus coal and X days of burning coal, and point out whether y is a linear function of X 3. Under normal circumstances, the maximum number of heart beats per minute (s / min) a person can bear during exercise is a function of the person's age of N years (1) According to the following information, the function of s with respect to n is obtained under normal conditions. According to the surface of scientific research in medicine, the heart rate of people during exercise is usually related to their age. Under normal conditions, the maximum heart rate that people aged 15 and 45 can bear during exercise is 164 beats / min and 144 beats / min respectively (2) If a 63 year old man is running and the doctor measures 26 beats in 10 seconds on the way, ask: is he in danger? Why? 4. It is known that y + m is in direct proportion to x-m (where m and N are constants). If x = - 1, y = - 15; X = 7, y = 1, find the relationship between Y and X 5. In the activity of Yunnan green hope project, the action of protecting mother river, a kind of telephone card was issued. The purpose is to build ten thousand mu of young people's new century forest at the beginning of the new century. The face value of this kind of telephone card is 12 yuan, of which 10 yuan is the call fee, 2 yuan is donated to Yunnan green hope project fund, and 1 yuan is attached to the call fee, Yunnan green hope project fund is the function y (1) Write the function relation between Y and X, and find the value range of the independent variable x (2) It is known that the cost of planting trees per mu is 400 yuan. If there are 46000 junior high school graduates in our city this year, and each person buys a card, how many mu of trees can the fund plant?
- 8. Given the sequence {a (n)}, a (1) = 1, a (2) = 2, a (n) = a (n-1) - A (n-2), (n ∈ n + and N ≥ 3), then s (100)=
- 9. On the properties of function periodicity If one of the following conditions holds for any X in the field of F (x), then f (x) is a periodic function, and the period T = 2A (a is not equal to 0) & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; f(x+a)=f(x)+1\f(x)-1 f(x+a)=1-f(x)\1+f(x) f(x+a)=f(x-a) How can I prove this
- 10. Function en, minimum positive period What is the minimum positive period of y = 2Sin μ x
- 11. Given the function f (x) = AX2 + BX + C, if f (0) = 0, f (x + 1) = f (x) + X + 1, find the expression of F (x) AX2 is the power of X
- 12. Simple function problems in senior one According to the previous production and sales experience of a product manufacturer, the following statistical rules about production and sales are obtained: the total cost of each product X (100 sets) is g (x) (10000 yuan), of which the fixed cost is 28000 yuan, and the production cost of each 100 sets is 10000 yuan. The sales income R (x) (10000 yuan) satisfies R (x) = - 0.4x ^ 2 + 4.2x (0 ≤ x ≤ 5) ）11 (x ＞ 5), assuming that the production and marketing of the product are balanced (that is, all the products produced can be sold) (1) Write the analytic formula of profit function y = f (x) (profit = sales revenue total cost) (2) How many products can the factory make the most profit?
- 13. 1. If the line y = - 2x + 3 intersects the parabola y = ax at two points a and B, and the coordinates of point a are (- 3,9), what are the opening direction, symmetry axis and vertex coordinates? 2. Given that the area of a rectangle is 6, find the functional relation between its length y and width x, and draw the image of this function in rectangular coordinate system 3. The quadratic function y = x-2x + 1 is known (1) Find the vertex a of this function image and the coordinates of its intersection B with y axis (2) Find the coordinates of the intersection points c and D of the function image and X axis; (3) Find ABC of s Triangle 3. The quadratic function y = 1 / 2x & sup2; - 2x + 1 is known (1) Find the coordinates of the vertex a of the function image and its intersection B with the y-axis. (2) Find the coordinates of the intersection points c and D of the function image and X axis; (3) Find ABC of s Triangle
- 14. On the concept of function continuity and the problem of limit F (x) = a (x = 1) f (x) = x ^ 3-1 / X-1, (x is not equal to 1) If f (x) is continuous on R, then a is equal to () LIM (an-1 / N + 2A / 3n)= n→∞ robin_ two thousand and six LIM (x → 1) (x ^ 3-1) / (x-1) how to deduce LIM (x → 1) (x ^ 2 + X + 1)
- 15. Is it necessary to define the partial derivative of a function at a certain point?
- 16. Given that the zeros of quadratic function f (x) = square of X + MX + n are - 1 and 2, then the solution set of inequality f (x) > 0 is
- 17. Let a be greater than 0, f (x) = e ∧ 2 / A + A / E ∧ X be the even function defined on R To prove that f (x) is an increasing function on (0, infinity)
- 18. Let FX be an increasing function defined on R +, f (x) = f (x / y) + F (y). If f (3) = 1, f (x) - f (1 / X-8) > 2, find the value of X Where > 2 has an equal sign, R + means 0 to positive infinity,
- 19. Given that the function f (x) is equal to {x2-a, X ≥ 0, 2x + 3, x < 0}, if the image of the function f (x) passes through the point (1, - 1) to find The second question about the value of F (f (0)) if the equation f (x) = 4 has a solution, find the value range of A
- 20. How to judge parity of mathematical function in grade one of senior high school Fast judgment of parity