Distance formula between two straight lines

When two straight lines are parallel: d = | c 1-C2 |/√ (a 2+b 2) When two straight lines intersect, the distance between them is 0. The distance from a point to a straight line is the length of the vertical line segment, which is the shortest of all the line segments connecting a point outside the straight line and all the points on the straight line. Of all the line segments connecting a point outside the straight line with a point on the straight line, the vertical line segment is the shortest, and the length of this vertical line segment.

Deduction: The distance between two parallel straight lines is the distance from any point on one straight line to another straight line. If P(a, b) is on the straight line Ax+By+C 1=0, then Aa+Bb+C 1=0, that is, Aa+Bb=-C 1, which satisfies the distance formula from point to straight line. +B？ )=|-C 1+C2|/√(A？ +B？ )=|C 1-C2|/√(A？ +B？ )。

The distance formula between two points is often used to find the distance between two points and the coordinates of points in a function diagram, and it is one of the distance formulas. The distance formula between two points describes the relationship between points and the distance between points. This part of knowledge teaching is small and simple. Through the slow teaching speed of teachers in class, we strive to make all-round students understand knowledge points and problem-solving methods. After class, the teacher assigns homework, and then through a lot of in-class and out-of-class exercises and out-of-class guidance, he repeatedly understands the knowledge until the students master it.