Length 指令

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範例：

Length( <向量> ) 產生此 <向量> 的長度。
Length( <點> ) 產生此 <點> 的位置向量長度。
Length( <串列> ) 產生此 <串列> 的長度，亦即此 <串列> 中元素的個數。
Length( <文字> ) 產生此 <文字> 的字元個數（譯註：不論全半形）。
Length( <軌跡> ) 回傳組成此 <軌跡> 的點個數。若要取得軌跡本身的長度，可使用 Perimeter_指令。returns the number of points that the given locus is made up of. Use Perimeter(Locus) to get the length of the locus itself. For details see the article about First Command.
Length( <圓弧> ) returns the arc length (i.e. just the length of the curved section) of an arc or sector.

Length( <Function>, <Start x-Value>, <End x-Value> ): Yields the length of the function graph in the given interval.; 範例： Length(2x, 0, 1) returns 2.236067977, about \sqrt{5}.
Length( <Function>, <Start Point>, <End Point> ): Yields the length of the function graph between the two points.; 備註： If the given points do not lie on the function graph, their x‐coordinates are used to determine the interval.
Length( <Curve>, <Start t-Value>, <End t-Value> ): Yields the length of the curve between the two values of the parameter.
Length( <Curve>, <Start Point>, <End Point> ): Yields the length of the curve between the two points that lie on the curve.

CAS Syntax

Length( <Function>, <Start x-Value>, <End x-Value> ): Calculates the length of a function graph between the two points.; 範例： Length(2 x, 0, 1) yields \sqrt{5}.
Length( <Function>, <Variable>, <Start x-Value>, <End x-Value> ): Calculates the length of a function graph from Start Point to End Point.; 範例： Length(2 a, a, 0, 1) yields \sqrt{5}.

備註： See also