1. Two knowledge points need to be sorted out in the second volume of senior two mathematics.
1. Definition and definition formula of linear function: Independent variable X and dependent variable Y have the following relationship:
y=kx+b
It is said that y is a linear function of x at this time.
In particular, when b=0, y is a proportional function of x.
Namely: y=kx(k is a constant, k≠0)
Second, the properties of linear function:
The change value of 1.y is directly proportional to the corresponding change value of x, and the ratio is k.
That is: y=kx+b(k is any non-zero real number b, take any real number)
2. When x=0, b is the intercept of the function on the y axis.
Iii. Images and properties of linear functions:
1. Practice and graphics: Through the following three steps.
(1) list;
(2) tracking points;
(3) The connection can be the image of a function-a straight line. So the image of a function only needs to know two points and connect them into a straight line. (Usually find the intersection of the function image with the X and Y axes)
2. Property: (1) Any point P(x, y) on the linear function satisfies the equation: y = kx+b (2) The coordinate of the intersection of the linear function and the y axis is always (0, b), and the image of the proportional function always intersects the origin of the x axis at (-b/k, 0).
3. Quadrant where K, B and function images are located:
When k>0, the straight line must pass through the first and third quadrants, and Y increases with the increase of X;
When k0, the straight line must pass through the first and second quadrants;
When b=0, the straight line passes through the origin.
When b0, the straight line only passes through the first and third quadrants; When k