Application of quadratic function If M teams participate in a game and every two teams play one game, the functional relationship between N and M is

Application of quadratic function If M teams participate in a game and every two teams play one game, the functional relationship between N and M is

N＝M×（M－1）÷2

Application of quadratic function
In a triangle with points a (2,3), B (0,0), C (3,0) as its vertices, the straight line part perpendicular to BC passing through point P (x, 0) on the bottom edge BC is divided into two parts ABC, and the area y of the part on one side of vertex B is expressed as a function of X

y=｛0 x≤0
3／4x2 x∈（0,2】
3+3／2（x-2）2 x∈（2,3）
9／2 x≥3

Practical problems of quadratic function in the third grade of junior high school
1. The symmetry axis of the parabola y = (k ^ 2-2) x ^ 2 + m-4kx is a straight line x = 2, and the lowest point is on y = - 1 / 2x + 2. Find the relationship of the quadratic function
2. The parabola y = x ^ 2 - (K + 3) x + 2k-1 is known. Let the parabola intersect with the X axis and two points a and B, the vertex of (a on the left) is C, and the ordinate of point C is m, and the value of (AB) ^ 2 / M is obtained

1. The axis of symmetry of the parabola y = (K & sup2; - 2) x & sup2; + m-4kx is a straight line x = 2, and the lowest point is on y = - 1 / 2x + 2. The equation of the axis of symmetry of the parabola y = (K & sup2; - 2) x & sup2; + m-4kx is x = - B / (2a) = 4K / [2 (K & sup2; - 2)] = 2, so: k = 2 or K = - 1 when k = 2, the parabola y = (k

A supermarket sells 2000 yuan refrigerators at 2400 yuan, with an average of 8 refrigerators per day
If the price of this refrigerator is reduced by 50 yuan, an average of 4 more refrigerators can be sold every day. Suppose that the price of each refrigerator is reduced by X Yuan, and the profit of this refrigerator is y yuan every day. Please write the analytic formula of the function between Y and X (it is not required to write the value range of the independent variable)

Suppose that the price of each refrigerator is reduced by X Yuan, and the profit of this refrigerator is y yuan,
y=(2400-2000-x)[8+x/50*4]=(400-x)(8+2x/25)