A function question in the second year of junior high school, a high score!

As the point of symmetry e(-1,-1,-1) of the point p with respect to the x-axis, connecting the x-axis of the eq to one point is the point r (because the straight-line distance between the two points is the shortest).

Because pr=pe, pr+qr=qe

Let the analytic expression of the primary function be y=kx+b, and substitute e(-1,-1),q(2,3) into y=4 3x+1 3

When y=0, x=-1 4

So r(-1 4,0).

Make the point p symmetrical point p1 (-1, -1) with respect to the x-axis, connect p1q to the x-axis, and the intersection point is r

Easy to calculate: the r-point coordinates should be (0,0).

Because pr=p1r, pr+qr=p1r+qp. The straight-line distance between the two points is minimal.

Let y=kx+b.Substituting the above test solution yields k=2 3 b=5 3 (so that p and q form a straight line, and the minimum distance is the straight line distance.) Therefore, the function relation is y=2 3x+5 3 r, and the coordinates of the point are so that y=0 is substituted into the relation, and the answer is x=-5 2, and the coordinates are (0, -5, 2).

p is the symmetry point e with respect to the x-axis, connecting eq, and eq is connected to the x-axis intersection point r coordinates, such that pr rq is the smallest, and the coordinates are r(-1 4,0).

Find the point p with respect to the point of symmetry p on the x-axis'(—1,-1), find p'q line, the intersection of the line and the x-axis is.

t=0，v=1200

t=50,v=200

It's a straight line, so v=kt+b

Substituting 1200 = 0+b

200=50k+b

b=1200,k=-20

v=-20t+1200

then t=10, v=-20*10+1200=10 million m v=-20t+1200<400

20t>1200-400=800

t>800/20=40

So in 40 days there will be a severe drought warning.

Due to the continuous drought, the water storage of a reservoir decreases with the increase of time, and the relationship between drought time t (day) and water storage v (10,000 cubic meters) is as follows"Fig"Shown ?:

What's your raw water volume?

Function: y= y=-x-7 y=4-2x y=-x y=4x y=-(2-x).

, the function in which the value of y increases with the increase of x is , and .

The function in which the value of y decreases with the increase of x is: ,

The function of increasing and increasing is 1, 3, 5, 6

The function of increasing and decreasing is 2,4,

where the function where the value of y increases with the increase of x is , where the function where the value of y decreases with the increase of x is , ,

The function that increases with the increase is:

The function that decreases as it increases is:

Functions that increase consequentially: 1, 5, 6

Functions that decrease consequentially: 2, 3, 4

The enlargement is:

The reduced is: by the way, this kind of problem, as long as you see whether the k value is positive, if it is positive, increase.

Enlarge and enlarge

The rest is reduced.

1 All 1, to make the quadrilateral ABCD a convex quadrilateral, then the quadrilateral is in the first quadrant, and the primary function y=mx+4 has a property: y decreases with the increase of x, and we can know that m<0, and when x=4, m -1 is obtained. Therefore, the value range of m is -1ed divided by ea=seven-quarters should be ed divided by ea=four-sevenths, and the following calculation is calculated according to this2, let e(x,0), according to the meaning of the title, ed:ea=ec:eb=4 7, that is, (x-4) (x-1)=4 7, the solution is x 8, so e(8,0), substitute it into y=mx+4, and find m=, so the analytic formula of the primary function at this time is y=.

Solution: (1) Y decreases with the increase of x.

m<0

The lines y=mx+4 intersect with the lines x=1 and x=4 at a and d a(1, m+4), respectively. d(4，4m+4)

Point A is within the first quadrant.

m+4>0

m>-4

The quadrilateral ABCD is a convex quadrilateral.

4m+4>0

m>-1

1

Substitute the dots. m=

m=Please select as, thanks!

1. The coordinate is (-3, 0) and the solution is 0

2. The abscissa is -2

You missed an x in the equation in your problem. I thought: it should be y=-( 3 3)x+2 3!

The coordinates of the point are: when y=0, x=6, so a(6,0); point b coordinates, when x = 0, y = 2 3, so b(0, 2 3).

The cd equation y= 3x+b, and after d((6+0) 2,(0+2 3) 2)=d(3, 3) points, substituting us gets:

3=3 3+b, b=-2 3, the equation cd:y= 3x-2 3, when y=0, x=2, that is, the coordinates of point c are c(2,0).

2.From a(6,0) and c(2,0), it can be seen that the perpendicular bisector equation of ac is x=(6+2) 2=4, then the intersection of this equation and the cd equation is found: the cd equation is y= 3x-2 3, and x=4 is substituted into it, and y=4 3-2 3=2 3, that is, (4,2 3) is the point that is found.

If the point can make adq acd, then the q point is the symmetry point of point c with respect to ab, and let the coordinates of the q point be x and y, there must be:

qx-dx=dx-cx,qx=2dx-cx=2*3-2=4;

qy-dy=dy-cy,qy=2dy-cy=2*√3-0=2√3

Therefore, the coordinates of the q point are (4,2,3).

①0=6k+b (1)

2 root number 3 = b (2).

1) (2) Solve the system of 2-element equations to obtain: y=(-root number3 3) x+2 root number3 Ab=4 root number 3 of the Pythagorean theorem, the push-out angle a=30 degreesAD=2 roots3AC=ADCoS30 degrees=4, and oc=2, so the coordinates of point C are (2,0) Point P is point C, because Cd is the perpendicular line of AB, so the distance from any point on Cd to AB is equal.