I'm a senior three, and I just reviewed this book recently. Let me tell you something about it. (1) The concept of linear inclination \ blunder! We forgot to mark the coordinates on the right with X and Y, and our math teacher will be scolded if he knows. Red. This is the tilt angle. I don't know the specific concept, but it's no use remembering the concept that I don't understand. Mathematics does not test concepts. Also pay attention to the range of tilt angle. 0 ≤α < 180 (2) Slope of a straight line: The tangent of the inclination angle α (α ≠ 90) of a straight line is called the slope of this straight line, and the slope is often expressed by lowercase letter K, that is, when the straight line L is parallel or coincident with the X axis, α = 0 and k = tan 0 = 0, k = tanα (/kloc-). ⑵ When the straight line L is perpendicular to the X axis, α = 90, and k does not exist. So the inclination angle α of the straight line L must exist, but the slope k does not necessarily exist. When k = tan α; 0, the inclination angle α is an acute angle; And when k = tanα=0, the inclination angle α is 0. (3) Equation of straight line 1, general formula: Ax times C=0 (where a and b are not 0 at the same time) 2. Point inclination formula: If a point (x0, y0) on the straight line is known and the slope k of the straight line exists, the straight line can be expressed as Y-. A straight line can be expressed as x=x0 3, oblique: on the Y axis, the intercept is b (that is, the intersection (0, b)), and a straight line with slope k can be obtained from the point oblique. Like point skew, the existence of k. 4 needs to be considered. Truncation torque formula: not applicable to straight lines perpendicular to any coordinate axis. Know that the straight line intersects the X axis (a, 0) and the Y axis. When ab is not 0, the skew formula can be written as x/a y/b= 1 5, and the two-point formula is a straight line (Y-Y 1)/(Y 1-) passing through (X 1) (X2, Y2).