Current location - Training Enrollment Network - Mathematics courses - Some math problems in the first volume of the second day of junior high school?
Some math problems in the first volume of the second day of junior high school?
First, multiple-choice questions (this big question * * 12 small questions, 3 points for each small question)

1. In the function, the value range of the independent variable x is ().

A. all real numbers B. all positive real numbers C. all negative real numbers D. all non-negative real numbers

2. In the function, the value range of the independent variable X is ()

A.x≥2 and x ≦-3b.x >; 2 and x ≠ 3 c.x ≥ 2 and x ≠ 3 d.x ≤ 2 and x≠-3.

3. If the point m (2m-3, 1) is in the second quadrant, the value range of m is ().

Morning & gtB. m<c. m≥d. m≤

4. If point P(m+3, m+ 1) is on the X axis of rectangular coordinate system, the coordinate of point P is ().

A.(0,-2)b .(2,0)c .(4,0)d .(0,-4)

5. Known function, when k takes a series of non-zero real numbers, its image is ()

A. Countless parallel lines B. Two parallel lines C. Countless straight lines intersect (0,-10)

D. Two straight lines intersect (0,-10)

6. The following relationship description correctly corresponds to the given function image (as shown in the following figure): ().

① the relationship between two adjacent sides y(cm) and x(cm) of a rectangle with a certain area;

(2) When the tractor is working, the fuel consumption per hour is the same, and the relationship between the remaining fuel quantity y(L) in the fuel tank and the working time x(h);

③ the relationship between the temperature y(℃) and the time x(h) in a city;

④ The relationship between the surface area y () of a cube and its side length x(cm).

A. relation ① corresponds to b, ② corresponds to c.b. relation ② corresponds to a, ③ corresponds to d.

C relationship ④ corresponds to a, ① to d, ③ to d and ④ to B ..

7. It is known that the resistance of a conductor at 0℃ is 2 ohms, and the resistance increases by 0.008 ohms every time the temperature increases by 65438 0℃, so the functional relationship between the resistance r (ohm) and the temperature t(℃) is ().

A.r = 0.008 TB . r = 2+0.008 TC . r = 2.008 TD . r = 2t+0.008

8. If a straight line is known and,, then the images of two straight lines (as shown in the figure below) may be ().

9. Among the following functions, the function in which y increases with the increase of x is ().

A.B. C. D。

10. Known, where is inversely proportional to, and the proportional coefficient is 0, which is directly proportional to, and the proportional coefficient is 0. If x=- 1 and y=0, then the relationship is ().

A.+b . = 1C。 -= 0D。 =- 1

1 1. There is a parallelogram with an internal angle of 120, and its perimeter is L. If one side of it is X and the other side adjacent to it is Y, then the functional relationship between Y and X and the value range of X are ().

A.,0≤x≤b,0 & ltx & lt

C., 0<x< finite, 0 ≤ x < L

12. For two objects A and B with constant stress areas respectively, the image of the functional relationship between compressive strength P (Pa) and pressure F (Niu) is a ray (as shown in the figure), then the following relationship holds ().

A.& ltB. ≤

C.& gtD. ≥

2. Fill in the blanks (this big question is ***8 small questions, with 3 points for each small question)

13. In the function, when x=, y = _ _ _ _ _ when x = _ _ _ _, y=- 1.

14. Monthly interest rate of current savings is 0. 14%. If you deposit 10,000 yuan, the functional relationship between principal and interest and Y yuan x months is _ _ _ _ _ _ _ _ _ _ _.

15. As we all know, the side length of a square is 2 cm. If the side length is increased by xcm, the functional relationship between the increased area y () and the increased side length x(cm) is _ _ _ _ _.

16. In the function, when a = _ _ _ _ _, it is a proportional function; When a = _ _ _ _ _, it is an inverse proportional function.

17. If the point p () is in the fourth quadrant, the linear function passes through the _ _ _ _ _ quadrant.

18. A coach company stipulates that passengers can carry a certain weight of luggage with them. If the weight exceeds the specified weight, they need to buy a baggage claim tag. The functional relationship between the baggage cost y (yuan) and the baggage weight x (kg) is shown in the figure. According to the image, answer:

(1) Carry15kg of luggage with you, and pay the baggage fee of RMB _ _ _ _ _ _ _ _ _;

(2) Carry 40 kilograms of luggage with you and pay the baggage fee of _ _ _ _ _ _ yuan.

(3) As long as the baggage you carry does not exceed _ _ _ _ kg, you don't need to buy a baggage ticket.

19. Known linear function

(1) When k = _ _ _ _ _, the straight line passes through the origin;

(2) When k = _ _ _ _ _, the straight line and the X axis intersect at point (0);

(3) When k = _ _ _ _ _, the intersection with the Y axis is below the X axis;

(4) When k = _ _ _ _ _, the straight line passes through the second, third and fourth quadrants.

Third, answer questions:

20. In the plane rectangular coordinate system, if point P (3a-9, 1-a) is in the third quadrant, and the abscissa and ordinate are integers, find the coordinates of point P .. (5 points)

2 1. It is known that the image of a linear function intersects the X axis and the Y axis at points A(m, 0) and B (0, n) respectively, and m = 3n. The triangle enclosed by this straight line and two coordinate axes has an area of 6 (square unit) (6 minutes).

(1) Find the values of m and n; (2 points)

⑵ Draw the image of this function in rectangular coordinate system.

22. Given that the straight line is parallel to the straight line, what are the characteristics of the intersection of the two straight lines and the Y axis?

23. It is known that the circumference of an isosceles triangle is 16cm. If the base length is ycm, the waist length is xcm(6 points).

(1) Write the functional relationship between y and x;

⑵ Find the range of independent variable x;

⑶ Draw an image of this function.

24. In order to encourage residents to save water, a city has made the following regulations on water consumption for residents: if the monthly water consumption of each household does not exceed 10 ton, it will be charged at per ton 1.5 yuan, and the excess will be charged at 2.00 yuan per ton. (6 points)

(1) Write the functional relationship between the water fee payable by each household w (yuan) and the monthly water consumption x (tons) (2 points).

(2) A household uses 8 tons of water in July and 0/5 tons of water in August. How much water does this family have to pay in July and August? (4 yuan)

25. The taxi fare standard of a city is: the starting price for a trip of less than 3km is 8 yuan, and the part exceeding 3km is charged 1.8 yuan. (6 points)

(1) Write the functional relationship between the fare y (yuan) and the distance x (km); (3 points)

⑵ After Xiaolong took a taxi to his destination, he hit 24.2 yuan on the electronic meter. What is Xiaoming's riding distance? (3 points)

26. There is a container with water inlet and outlet pipes, and the amount of water in and out per unit time is constant. Suppose that water only flows in for 4 minutes from a certain moment, and then both water and water flow in the next 8 minutes, and the relationship (7 minutes) between time x (minutes) and water storage capacity y (liters) of the container as shown in the figure is obtained.

(1) How much water per minute? (2 points)

⑵ When 4≤x≤ 12, what is the relationship between x and y? (2 points)

(3) If only water comes out after 12 and there is no water, find the expression of y .. (3 points)