As shown in the figure, the parabola y = 1 / 2x + MX + n (n ≠ 0) intersects the straight line y = x with two points AB, intersects the Y axis with points c, OA = ob, BC parallel to the X axis (1) The analytic formula of parabola (2) Let D and E be the two moving points on the line AB which are different from a and B (point E is above point d) de = root 2. Let D and E be parallel lines of Y axis, intersecting parabola and points F and g respectively. Let the abscissa of d be x and the area of quadrilateral degf be y. find the analytic expression of y about X, write out the value range of independent variable x, and find the maximum value of y when x is the value

As shown in the figure, the parabola y = 1 / 2x + MX + n (n ≠ 0) intersects the straight line y = x with two points AB, intersects the Y axis with points c, OA = ob, BC parallel to the X axis (1) The analytic formula of parabola (2) Let D and E be the two moving points on the line AB which are different from a and B (point E is above point d) de = root 2. Let D and E be parallel lines of Y axis, intersecting parabola and points F and g respectively. Let the abscissa of d be x and the area of quadrilateral degf be y. find the analytic expression of y about X, write out the value range of independent variable x, and find the maximum value of y when x is the value


1. BC ‖ X axis. X = 0, OC = - N - n = - 2n under the root sign, the solution is n = - 2
The analytical formula of parabola is y = 1 / 2x2 + X-2
2 (1) de = root 2, the abscissa of point D is x, (point E is above point d), so D (x, x) e (x + 1, x + 1), x + 1



If the intersection of the line y = - x-3 and the line y = 2x + 4 is in the first quadrant, then the value range of M is(
A.1<m<7
B.3<m<4
C.m>1
D.m<4


The straight line y = - x-3 moves m units upward, and the equation becomes y = - x-3 + M
The intersection with the line y = 2x + 4 is in the first quadrant,
2x+4=-x-3+m
3x=m-7
x>0
m-7>0
m>7
There is no answer
If the title is a straight line y = - x + 3, then
2x+4=-x+3+m
3x=m-1
x>0
m-1>0
m>1
The answer is C



(2013 · Tai'an) after the straight line y = - x + 3 is moved upward by M units, and the intersection point with the straight line y = 2x + 4 is in the first quadrant, then the value range of M is ()
A. 1<m<7B. 3<m<4C. m>1D. m<4


After the straight line y = - x + 3 moves m units upward, we can get: y = - x + 3 + m, the analytic formula of two straight lines is: y = - x + 3 + my = 2x + 4, the solution is: x = m − 13y = 2m + 103, that is, the intersection coordinate is (m − 13, 2m + 103), ∵ the intersection is in the first quadrant, ∵ m − 13 > 02m + 103 > 0, the solution is: M > 1



In the plane rectangular coordinate system, the line y = 2x + 1 is translated by 3 √ 2  ̄ units along the ray ocy = x direction, and the analytical expression of the translation line is obtained


First of all, the coordinate a of the intersection point of two straight lines is found to be (- 1, - 1) 3 √ 2  ̄ units along the ray ocy = x direction, which can be divided into two kinds: (1) 3 units of length are translated to the right, and 3 units of length are translated up at the same time. In this case, the coordinate of point a after translation is (2,2)