连接点 (2, 3) 和 (3, 7) 的线段除以 Y 轴的比例是多少?
数学是一门与数字和计算相关的学科。并且,根据计算类型,数学分为不同的分支,如代数、几何、算术等。几何是处理形状及其属性的数学分支。处理涉及坐标的点、线和平面的几何称为坐标几何。
坐标
平面上任意一点的位置可以表示为(x, y),这些对被称为坐标,x是平面上一点的水平值。这个值也可以称为x坐标或横坐标,y是平面上一点的垂直值。该值可以称为 y 坐标或纵坐标。在坐标几何中,点表示在笛卡尔平面上。
除以 y 轴表示位于 y 轴上的点。
位于 y 轴上的点的 x 坐标始终为零。
截面公式
如果一条线 AB 分别具有点 A 和 B 的坐标 (x 1 , y 1 ) 和 (x 2 , y 2 ),并且线 AB 上有一个点 C 将该线以 m:n 的比例划分,则C可由下式求得,称为截面公式:
- x = (mx 2 + nx 1 ) /( m + n)
- y = (我的2 + ny 1 ) / (m + n)
连接点 (2, 3) 和 (3, 7) 的线段除以 Y 轴的比例是多少?
解决方案:
In the above problem statement, there is one line segment say AB having coordinates (2,3) and (3,7) of A and B respectively. Let’s consider a point C having coordinate (x, y) which lies on the y-axis, then the x coordinate of point C is 0, the coordinates of C can be written as (0, y).
Find the ratio in which this C point will divide the line segment AB. To find the ratio, use the section formula of coordinate geometry. Let’s assume that point C divides AB into a k:1 ratio.
As known, the x-coordinate of point C, we can use it to obtain the value of k and get the ratio. Here,
m = k, n =1
x1 = 2, y1 = 3
x2 = 3, y2 = 7
x- coordinate using section formula:
x = (mx2 + nx1) / (m + n)
After substituting the values,
x = ((k)(3) + (1)(2))/ (k +1)
0 = (3k + 2)/ (k + 1)
0 = 3k + 2
– 2 = 3k
-2/3 = k
C divides the point in ratio k:1 = -2/3:1, therefore ratio is 2:3
A negative sign represents that point C divides the line segment externally in ratio 2:3.
示例问题
问题1:连接点A和B的线段坐标(0,-2)和(3,1)分别除以X轴的比例是多少?
解决方案:
Let C be the point on X-axis that divides AB in ratio k: 1. As C lies on the x-axis, the y-coordinate of the C should be 0. Therefore, the coordinate of C : (x, 0). As known as the y-coordinate of point C, we can use it to obtain the value of k and get the ratio. Here,
m = k, n = 1
x1 = 0, y1 = -2
x2 = 3, y2 = 1
y- coordinate using section formula:
y = (my2 + ny1) / (m + n)
After substituting the values,
y = ((k)(1) + (1)(-2))/ (k +1)
0 = ( k – 2)/ (k + 1)
0 = k – 2
2 = k
2 = k
C divides the point in ratio k:1 = 2:1, therefore ratio is 2:1.
问题2:点(2,2)以什么比例分割线段AB,其中(0, 0)和(5, 5)分别是A和B的坐标。
解决方案:
Let (2, 2) divide AB in ratio k: 1. As known the a and y-coordinate of point, use it to obtain the value of k and get the ratio. Here,
m = k, n = 1
x1 = 0, y1 = 0
x2 = 5, y2 = 5
y- coordinate using section formula:
y = (my2 + ny1) / (m + n)
After substituting the values,
2 = ((k)(5) + (1)(0)) / (k + 1)
2 = ( 5k ) / (k+1)
2(k + 1) = 5k
2k + 2 = 5k
2 = 3k
2/3 = k
Hence, (0, 0 ) divides the point in ratio k:1 = 2/3:1, therefore ratio is 2:3.