求连接点 (- 3, 10) 和 (6, -8) 的线除以点 (- 1, 6) 的比率?
我们熟悉在平面图上绘制点。点通常用于定位称为坐标的点。坐标几何是处理坐标、坐标之间的距离、两个坐标之间的中点、以特定比例划分线的点……等的研究分支。坐标几何通过使用方程、直线将代数和几何联系起来。作为坐标的点的位置使用有序的数字对表示,其中第一个数字表示平面的 x 轴,而其他数字表示 y 轴。
截面公式
截面公式用于找到以已知比率划分线段的点,并且线段的坐标已知。如图所示,如果在 P(x 1 , y 1 ) 和 Q(x 2 , y 2 ) 的平面上的线段 PQ 除以点 A(x, y),比例为 m:n,则点可以使用截面公式找到 A。我们也可以通过比例为 1:1 来找到线段的点。
A (x, y) = ((mx 2 + nx 1 ) / (m + n), (我的2 + ny 1 ) / (m + n))
如果在外部划分线段的点,则外部部分是
A (x, y) = ((mx 2 – nx 1 ) / (m – n), (my 2 – ny 1 ) / (m – n))
求连接点 (- 3, 10) 和 (6, -8) 的线除以点 (- 1, 6) 的比率?
解决方案:
Given,
Points of line segment: (-3,10) (6,-8)
Point dividing line segment: (-1,6)
Since, the point is dividing the line segment internally we use section formula:
A (x, y) = ((mx2 + nx1) / (m + n), (my2 + ny1) / (m + n))
By substituting values as x = -1, y = 6, x1 = -3, x2 = 6 we get
=> -1 = (6m + (-3n))/(m + n)
=> -1(m + n) = 6m – 3n
=> -m – n = 6m -3n
=> -m – 6m = n – 3n
=> -7m = -2n
=> m / n = 2/7
=> m : n = 2 : 7
Therefore, ratio in which point(-1, 6) divides the line segment joining (-3, 10), (6, -8) is 2:7
中点公式
中点被定义为将线段精确地分成两半的点,我们可以从截面公式中得出中点公式。如果点 A(x, y) 以 1:1 的比例分割连接 P(x 1 , y 1 ) 和 Q (x 2 , y 2 ) 的线段,则称 A 为线 PQ 的中点。
通过使用截面公式:
A (x, y) = ((mx 2 + nx 1 ) / (m + n), (我的2 + ny 1 ) / (m + n))
因为,m : n = 1 : 1
A (x, y) = (((1)x 2 + (1)x 1 ) / (1 + 1), ((1)y 2 + (1)y 1 ) / (1 + 1))
A (x, y) = ((x 2 + x 1 ) / 2, (y 2 + y 1 ) / 2)
示例问题
问题1:三等分点是什么意思?
解决方案:
Point of Trisection is two points on line segment where the line is divided into 3 equal parts.
If a point P,Q is a point of trisection for line segment AB then AP : PQ : QB = 1 : 1 : 1
问题 2:求以 1:2 的比例划分连接点 A (2, 1) 和 B (2, 7) 的线段的点的坐标?
解决方案:
Given,
Points of line segment : (2,1) (2,7)
ratio in which line segment is divided is 1 : 2
Since, the point is dividing the line segment internally we use section formula:
A (x, y) = ((mx2 + nx1) / (m + n), (my2 + ny1) / (m + n))
By substituting values as m = 1, n = 2, x1 = 2, x2 = 2, y1 = 1, y2 = 7 we get
A (x, y) = ((1*2 + 2*2) / (1 + 2), (1*7 + 2*1) / (1 + 2))
A (x, y) = (6/3, 9/3)
A (x, y) = (2, 3)
Therefore, point that divides the line segment joining points A (2, 1) and B (2, 7) is (2, 3)
问题 3:求连接 A (5, 3) 和 B (3, 7) 的线段的中点?
解决方案:
Given,
Points of line segment : (5,3) (3,7)
Mid point formula:
A (x, y) = ((x2 + x1) / 2, (y2 + y1) / 2)
A (x, y) = ((5 + 3) / 2, (3 + 7) / 2)
A (x, y) = (8 / 2, 10 / 2)
A (x, y) = (4, 5)
Therefore, Midpoint of the line segment joining A (5, 3) and B (3, 7) is (4, 5)
问题 4:点 (2, 1) 和 (2, 7) 的连接除以点 (2, 3) 的比率是多少?
解决方案:
Given,
Points of line segment: (2,1) (2,7)
Point dividing line segment: (2,3)
Since, the point is dividing the line segment internally we use section formula:
A (x, y) = ((mx2 + nx1) / (m + n), (my2 + ny1) / (m + n))
By substituting values as x = 2, y = 3, y1 = 1, y2 = 7 we get
=> 3 = (7m + n)/(m + n)
=> 3(m + n) = 7m + n
=> 3m + 3n = 7m + n
=> -7m + 3m = n – 3n
=> -4m = -2n
=> m / n = 2/4
=> m : n = 1 : 2
Therefore, ratio in which point(2,3) divides the line segment joining (2,1),(2,7) is 1:2