First, multiple-choice questions (3 points for each small question, 30 points for * * *)
1. Inverse proportional function y=
The image of is located in quadrant A, quadrant I and quadrant II.
The first and third quadrants
Second and third quadrants
D, second and fourth quadrants
2. If 2y-7x = 0, then x: y equals a and 7: 2.
B, four to seven
c、2∶7
d、
7∶4
3. If the similarity ratio of two similar triangles is
Then their area ratio is (
)A.B。
C.
D.
4. If the area of a triangle is known to be constant, then its base.
tall
Bottom edge
The functional relationship between images is roughly (ABcD5,
quadratic function
An image can be represented by a quadratic function.
Picture translation, the following translation is correct (
(a) First translate 2 units to the left, and then translate 1 unit upward. First, translate 2 units to the left, and then translate 1 unit down. First translate 2 units to the right, and then translate 1 unit up. First translate 2 units to the right, and then translate 1 unit down. 6. As shown in the figure, parabola.
The symmetry axis of is a straight line.
, and through the point.
(3,0), then
The value of is (
A.
B.
- 1
C.
1
D.
2
7. As shown in the figure, there is a central angle of 120.
O, a sector with a radius of 6cm, if OA and OB overlap to form a cone edge, then the height of the cone is (
)a。
centimetre
B.
centimetre
C.
centimetre
D.
Cm8 .. As shown in the figure, the circle inscribed quadrilateral ABCD consists of four congruent isosceles trapezoids, and the diameter of AD is ⊙O, then the degree of ∠BEC is (
)
A. 15
b30
C.45
Cao 60
9. The picture shows Xiao Ming's schematic design of measuring the height of the ancient city wall with a flashlight. Place a horizontal plane mirror at point P,
It is known that the light emitted from point A is reflected by the plane mirror, which just hits the top C of the ancient city wall CD.
AB⊥BD,CD⊥BD，
And measured AB = 1.2m, BP = 1.8m, PD = 12m, then the height of the ancient city wall is (
)a。
6 meters
B.
8 meters
C.
18m
24 meters in diameter
10. Make a ring with metal wire on the equator of the globe. Now that the hoop radius is increased by 1m, it is necessary to add m meters of wires. Suppose there is an iron hoop on the equator of the earth, and the same radius increases by 1m, and it is necessary to increase the length of wires by n meters, then the size relationship between m and n is ().
A, m > n b, m < n c, m = n d, uncertain.
Fill in the blanks (4 points for each small question, 24 points for * * *)
1 1, in the inverse proportional function y=
On each curve of the image, y decreases with the increase of x, so the value range of k is 12, as shown in the figure, the radius OA of ⊙O is 10 cm, the chord AB is 16 cm, and P is a moving point on AB, so the shortest distance from point P to the center of O is
Centimeter.
13. Write a parabola to make it pass the origin, and the analytical formula is 14. As shown in the figure, point D and point E are on AB and AC on the △ABC side, respectively, and
If DE=3, BC=6 and AB=8, the length of AE is 5. In △ABC, d is on AB, DE∨BC,
If the area of △ABC is 9, then the area of △ADE is 16. As shown in the figure, in the plane rectangular coordinate system, point A 1 is the intersection of a circle with radius 2 and a straight line L 1 passing through this point (0,1) and parallel to the X axis; Point A2 is the intersection of a circle with the origin O as the center and a radius of 3 and a straight line l2 passing through point (0,2) and parallel to the X axis; ..... according to this rule, click a coordinate of III. Solve the problem (there are ***8 questions in this question, with ***66 points)
17, (6 points) known inverse proportional function
Through point A (2 2,3 (1), find the analytical expression (2) of this function, and find the value range corresponding to y when x≥3. 18, (6 points) as shown in the figure: there are △ABC and △DEF on the square grid, which shows that these two triangles are similar, and their similarity ratio is obtained.
19(6 points) Known quadratic function
The image is as shown in the figure:
(1) Find the analytic function
(2) Write the symmetry axis. When answering the question of what is the value of X, does Y decrease with the increase of X? 20.(8 points) As shown in the figure,
One,
b，
c，
D is at four o'clock,
AD is the diameter ⊙O, AD=6cm, if
∠ ABC =∠ CAD。 Find the length of AC 2 1. (8 points) A farmer produces and distributes an agricultural and sideline product, and the cost price of the product is known as 20 yuan/kg. According to market research, the daily sales volume w (kg) of this product has the following relationship with the sales price x (yuan /kg): w =-2x+80.
(2) When the sales price is set at how much yuan, the daily sales profit is the largest? What is the maximum profit?
(3) If the price department stipulates that the sales price of this product should not be higher than 28 yuan/kg, and farmers want to get daily sales profit 150 yuan, what should the sales price be?
Try to prove your conclusion.