Bezier曲線與蚶線間之關聯性的探討與推廣
在這篇報告中,我們以貝斯曲線的做圖原理建立出一種新的曲線-環狀貝斯曲線,進而得到不少有趣的結果。我們發現有名的古典曲線-蚶線,也是屬於二次環狀貝斯曲線。軌跡方程式為:,此時,係數恰符合二項式定理。之後我們推廣至n次環狀貝斯曲線的軌跡方程式:,也符合二項式定理。
在複數平面上,給定z0、z1、z2三點,我們定義出一個二次變換 ,若,,可映射成蚶線的圖形;若z∈實數,則可映射成拋物線。利用此結果類推我們找到一個複數平面上由 z0、z1、...、zn 所決定的n次變換將以原點為圓心的單位圓,映射成n次環狀Bezier曲線。
In this essay, we use the method of forming a Bezier Curve to establish a new curve, circular Bezier Curve, and find a lot of interesting results. We discover the famous classical curve "limacon", which belongs to the Quadratic Circular Bezier Curve. The locus of Quadratic Circular Bezier Curve is, where. Its coefficients match the binomial theorem. Then we apply it to the locus of nth-circular Bezier Curve:, and it also matches the binomial theorem.On the complex plane, we define a quadratic transformation corresponding to three points—z0,z1 and z2 as .If , where , a limacon is mapped. If z is a real number, a parabola is mapped. With this result, we will find a nth transformation defined by z0、z1、...、zn on the complex plane. It will form a nth-circular Bezier Curve with unit circle centering on the origin.
重複圖形
「重複圖形」是本篇報告研究的問題,我們利用「方程式」建立一個尋找重複圖形,並証明其個數的方法。利用此方法得出下面的結論:1.會形成lap 2 的凸多邊形只有2 種,即三角形和四邊形。(1)「lap 2 三角形」只有1 種,即等腰直角三角形。(2)「lap 2 四邊形」只有1 種,即二邊之比為1: 且內角是45°、135°的平行四邊形。2.會形成lap 3 的凸多邊形只有2 種,即三角形和四邊形。(1)「lap 3 三角形」只有1 種,即內角為30°–60°–90°的直角三角形。3.其他的lap k 三角形:(1)任意內角為30°–60°–90°的直角三角形都是lap 3k²,其中k是正整數。(2)邊長比為1:m: 的直角三角形是lap (m²+1)k²三角形,其中m、k是正整數。
To find repeated figures, we construct a method to search them with the help of algebraic equations. Here we arrive at:1. There are only two kinds of lap 2 convex polygons, triangles and quadrilaterals. (1) The only lap 2 triangle is isogonal right-angled. (2) The only lap 2 quadrilateral is the one that contains angles 45°, 90° and two neighboring sides with the ratio 1: . 2. There are also two kinds of lap 3 convex polygons, triangles and quadrilaterals. (1) The only lap 3 triangle is the one with angles 30°, 60° and 90°. 3. Other kinds of lap k triangles are listed as following: (1) A triangle with angles 30o, 60°, 90° is a lap 3k², the k is a natural number. (2) A right-angled triangle whose ratio is 1 : m : is a lap (m2+1)k², the m and the k are natural numbers.
共點圓、共圓點
我的研究是利用一些特殊的手法來探討所有情況皆會產生共點圓或共圓點。在一個由四條直線(無平行線組、無共點)所構成的圖形中,可以找到四個三角形及它們的外接圓。我知道它會共點,在此稱其為限制點。且若再添加一條直線,則可以任意的取出四條直線,分別找出它的限制點,而這些限制點又會共圓,吾稱其為限制圓。我欲證明此種情況會不斷延續下去。即是六條線時又會有限制點,七條線時又會有限制圓…。在本研究中,我利用了數學歸納法、特殊的編號方法以及「方向角」來做出此證明。由於固定的線組對應至固定的限制點或限制圓,希望能向找出其性質的方向發展。In my study, I use some skills to discuss all the situations which satisfy following conditions. The result is that concurrent circles or concyclic points will be found in every situation. In a graph consisting of four lines, conforming to conditions that any three lines won’t be parallel or intersect at one point, I can find out four triangles and their circumscribed circles. I know these circumscribed circles will be concurrent and I call the point at which all the circles meet “restricted point”. If another line is additionally added in the graph, I can discover that restricted points determined by any four lines in the graph will be concyclic. I call the circle “restricted circle”. What I want to prove is that the above situation will go on. In other words, restricted points will exist when I have six lines, and restricted circles will exist when I have seven lines and so on. In my study, I used Principal of Mathematical Induction, special ways of numbering points and circles, and “orientated angle” to prove my hypothesis. Because of particular line groups corresponding with particular restricted points or restricted circles, the further work I want to attain is to find the relation of them.
四面體體積平分面的包絡方程探討
剛開始考慮平分物件時,我們從二維的多邊形部分著手,後來發現已經有人做過相關研究,並且得到類似的結論。這個部份顯現出面積平分線與其包絡曲線間的密切關係。我們將其中的方法和結果加以歸納、改善,為了更全面地研究,我們推導出一般性的包絡方程。之後當我們推廣到三維領域時,發現四面體體積平分面與之前的結論有些相似之處,平分的情況卻也更複雜,我們將推導的結果用電腦軟體呈現出來,以便更深入地了解它。最後嘗試了相當抽象的高維積平分,結果仍具有工整的對稱性,讓我們充分領略了數學之美!When considering bisecting a subject, at first we focused our attention on 2-D case, polygons. But afterwards, we found there were already some similar studies conducted by other students, which indicated the close relation between the area-bisecting lines of a polygon and their envelope. We rearranged their methods and results, and then made further improvement. Moreover, in order to study the bisecting problem entirely, we derived the general envelope equation. Then when extending the generalization to the 3-D case, we came to the conclusion that tetrahedrons’ volume-bisecting planes is similar to that in 2-D, but the circumstances are more complex. We tried to show our result with the aid of software, hoping to understand it fully. Finally, we tried to do the case in higher dimension, which is very abstract, and the result was clear-cut symmetrical. During the studying process, we had seen “the beauty of mathematics.”
二次函數上正三角形建構之研究及探討
在拋物線上置掛正三角形看似簡單,其實不然。本篇文章研究在二次函數的各種不同情況下,可做正三角形的分佈以及其個數。
1. 在一條拋物線上時,最多只能作正三角形。
4. 在三條對稱軸相等的拋物線和共頂點開口大小不同之拋物線上,本篇文章證明一定能找出正三角形落在它們之上。但由於最多有四個分界點,要解四次方乘組過於繁複,於是本篇文章對分界點作了一些估計,找出了分界點的極限值。
5. 本篇文章證明了對於給定的正n 邊形,存在一1 元n-1 次方程式可以通過它所有頂點。
Building a regular triangle on a parabolic curve looks easy . In fact , it doesn’t . This Article researches regular triangles distributions and its numbers in different conditions.
1. On one parabolic curve can only build regular triangles , squares and other regular polygons can’t be built.
4. For three parabolic curves which has same symmetrical axis or three concurrent parabolic curves, we prove that it can build at least one regular triangle on them .But because it can have at most 4 boundary points, to solve quartic equation is to complicated. So we do some estimation of boundary points, and find out some limits.
5. This Article prove that for given regular polygons , there exists a one dimension n-1 orders equation can pass all its apexes.
蜘蛛數
We understood the definition and meaning of spider number by reading〝Wonders of Numbers〞. It interested us so much. So, we took further step to study the situation of extreme value when the gap sometimes lie on the line and sometimes on the circle or even on both. That is to say, we explored the relation between spider number and the gap when the spider number is maximum or minimum. New research for the application of spider number involves several directions. First, we design a new game called〝Stepping Land Mine〞with the rule of spider number. Give you a net with several hidden gaps, trying to find the right positions of gaps. Second is the further result for a different type of net about regular n-polygon. Third is a tactic for a net with destroying of the strategy points. In this situation, the gaps amount on the circle and on the line are fixed. At the same time, consider the situation of circles and lines designing the tactic of placing the gaps to attain the maximum of the destructive effect. 在本文中我們定義一個蜘蛛網上的蜘蛛數,若在蜘蛛網中加入缺口後,會影響蜘蛛數的大小。我們探討蜘蛛網上的缺口,該如何分配才能夠得到蜘蛛數的極值(最大值及最小值)。先觀察一直線和圓上缺口如何放置蜘蛛數有極值,再探討許多條直線及圓上的情況,進而推展至許多同心圓及通過圓心的許多條放射線的缺口,該如何放置,蜘蛛數才會有極值發生。
「圖形板」的圖形軌跡之探討及其延伸
Starting from the problem in AMC competition of Australia, we try to find out the locus and its length when a point in a regular polygon rolls in a circle. The result is that the locus has a wonderful and regular cycle.Next, we discuss the regularity of the cycle when a regular polygon(n sides) rolls in another regular polygon. Furthermore,we discuss the the equation of the locus by changing the radius and the angle of rolling. we find out the argument function of the locus of a point inside when a a regular polygon(n sides)rolls in another regular polygon (m sides): , Aj is the summits of the regular polygon(m sides), Bjcorresponds Aj when a point inside the regular polygon (n sides) rolls, ) And then, we do some moving simulation with some computer math software, such as Cabri Geometry、Mupad, etc. We discuss the regularity of the locus and its equation of a point inside when some special cycloids, like asteroids, cardioids, etc, roll in a certain condition. Moreover, with the result of research 2, we create the “plate" and apply for a patent on it. We hope to study math by playing games.
從澳洲AMC 競賽題出發,嘗試探討一正n 邊形中的一點在單位圓內滾動軌跡及其軌跡長度,發現該軌跡均會產生奇妙的循環規律。
接下來,推廣探討正n 邊形在其他正多邊形中滾動時循環的規律,並利用旋轉半徑及角度之間的變化深入探討其滾動軌跡方程式,發現正n 邊形繞正m 邊形滾動時其內部一點軌跡參數式為,其中, Aj 為 正m 邊形之各頂點、Bj 為正n 邊形中內部一點旋轉時對應 Aj 之點,。
進一步想嘗試使用數學電腦軟體如:Cabri Geometry、Mupad 等對以上研究去做一些動態模擬,並再探討一些特殊擺線如:星狀線、心臟線…等,在條件下相切滾動時,圖中某一點的軌跡規律性及其方程式。另外,應用研究二中的結果,創造出寓數學於遊戲的「圖形板」,並申請了新型專利。