學校圖書館檢來一本舊教科書,名為 Applied Numerical Analysis。
在解方程一章,以下例引起動機。
If you worked for a mining company the following might be a typical problem:
There are two intersecting mine shafts that meet at an angle of 123, as shown in the figure above. The straight shaft has a width of 7 feet, while the entrance shaft is 9 feet wide. What is the longest ladder that can be negotiate the turn? You can neglect the thickness of the ladder members, and assume it is not tipped as it is maneuvered around the corner. Your solution should provide for the general case in which the angle, A, is a variable, as well as the widths of the shafts. (more…)