Revision on equation of Straight line

Consider the straight line passing through points A and B. C is a point on the straight line. 考慮穿過A，B兩點的直綫。C是綫上一點。

1. Let C be (x,y).

[size=150](a) From the graph, Which of the following conditions does C satisfy? [br] 由圖中可得，點C滿足以下哪個條件?[/size]

AC=AB slope of AC = slope of AB

[size=100][size=150](b) From (a), determine which of the following equations does C satisfy? [br] 由(a)，點C滿足以下哪條等式?[/size][/size]

[math]\sqrt{\left(4-2\right)^2+\left(5-1\right)^2}=\sqrt{\left(y-4\right)^2+\left(x-5\right)^2}[/math] [math]\frac{y-4}{x-5}=\frac{4-2}{5-1}[/math]

[size=150][size=200]Since every points on the straight line satisfy the equation above, the equation above is the equation of the straight line.[br]因爲直綫上的任意點均滿足上述式，因此上述式就是這條直綫的方程。[/size][/size]

2. 透過化簡上述式，可得以下直綫方程。

Conclusion

[size=150][size=200]Therefore, to find the equation of any shape, we just need to find an equation that every points on the shape satisfy.所以，求任意圖形的方程，我們衹需要找出圖形上任意點都滿足的一條等式。[/size][/size]

Revision on equation of Straight line

Consider the straight line passing through points A and B. C is a point on the straight line. 考慮穿過A，B兩點的直綫。C是綫上一點。

1. Let C be (x,y).

2. 透過化簡上述式，可得以下直綫方程。

Conclusion

Information: Revision on equation of Straight line