函数总结大全(国外英语资料).docVIP

函数总结大全(国外英语资料) Primary function Definitions and definitions: The independent variable x has the following relationship with the dependent variable y: Y=kx+b At this point, y is called a function of X. In particular, when b=0, y is the positive function of X. Namely: y=kx (k is a constant, k = 0) Two, the nature of a function: The change value of 1.y is in direct proportion to the change of the corresponding x, and the ratio is k That is, y=kx+b (k is any real number that is not zero, B takes any real number) 2., when x=0, B is the intercept of the function on the Y axis. Three, the image and properties of a function: 1. methods and graphics: through the following 3 steps (1) list; (2) tracing points; (3) wired, you can make a function of the image - a straight line. Therefore, the image that functions once only needs to know 2 points and can be connected in a straight line. (usually find the intersection of the function image with the X axis and the Y axis) 2. properties: (1) at any point on a function, P (x, y) satisfies the equation: y=kx+b. (2) the coordinates of the intersection of the first function and the Y axis are always (0, b), and the X axis is always handed to (-b/k, 0) the image of the positive scale function is always past the origin. 3.k, B, and the quadrant of the function image: When k 0, the line passes through one or three quadrants, and Y increases with the increase of x; When k 0, the line passes through the two and four quadrants, and the Y decreases with the increase of X. When b 0, the line must pass through the one or two quadrant; When b=0, the line passes the origin When B is 0, the line must pass through the three or four quadrant. In particular, when b=O, the line represents an image of the positive scale function through the origin O (0, 0). At this point, when k 0, the line passes only one or three quadrants; when k is 0, the line passes through the two and four quadrants. Four, determine the expression of a function: The known poi