Y has the following relationship with the linear function of the independent variable X: 1.y=kx+b (k is an arbitrary constant other than 0 and b is an arbitrary constant). When x takes a value, y has one and only one value corresponding to x, and if there are two or more values corresponding to x, it is not a linear function. X is an independent variable, Y is a function value, K is a constant, and Y is a linear function of X. Especially when b=0, Y is a proportional function of X, that is, the image of the proportional function of y=kx (k is a constant, but K≠0) passes through the origin. Definition domain (function value): the range of independent variables, which should make the function meaningful; It should be realistic. Common representation methods: analytical method, image method and list method.

Edit the related properties of this paragraph.

Function property: the change value of 1.y is in direct proportion to the change value of x, and the ratio is k.K is constant, that is, y=kx+b(k, b is constant, k≠0), ∫ when x increases m, k (x+m)+b = y+km. 2. When x=0, b is the point of the function on the Y axis, and the coordinate is (0, b). When b=0 (y=kx), the image of a linear function becomes a proportional function, which is a special linear function. 4. In two linear function expressions: when k and b in the two linear function expressions are the same, the images of the two linear functions coincide; When k is the same and b is different in the expression of quadratic function, the images of quadratic function are parallel; When k and b in two linear function expressions are different, the images of two linear functions intersect; When k is different and b is the same in quadratic function expressions, the images of quadratic functions intersect at the same point (0, b) on the Y axis. If the relationship between two variables X and Y can be expressed as y = kx+b (k both K and B are constants, and K is not equal to 0), then Y is said to be a linear function of X..