The series expansion (级数展开式) of sine function at a given x using n terms (项) is

这个附件的图。。。
(1) Write an M-file named “sine.m” which contains a function. The function computes the
value of sine function using the above expansion at a given x using n terms. In other
words (换句话说), the function sine(x,n) returns (返回) the value of the expansion at x
and the value is calculated using n terms.
(2) Matlab has a built-in (内建) sine function named “sin” which computes the value of sine
function at a given x. As you can imagine (想象), the values obtained by using theexpansion may not be the same with the results returned by the sin function used by Matlab. See the data in the following table for an example.
The number of n    Sin(π/4)    Sine(π/4,n)
        1                        0.707106… 0.785398…
    2                        0.707106… 0.704652…
    3                        0.707106… 0.707143…
    4                        0.707106… 0.707106…
    As you may have noticed from the table, for a given point π/4, the larger the number n is,
the closer the values obtained by using the expansion are to the actual values calculated
by the sin function in Matlab. Now a question rises: in order to achieve (达到) a certain
degree of accuracy (精确度), how many terms should be used in the expansion in
approximating (近似计算) the value of sine function?
To answer this question, write another M-file named “computeN.m” which finds the
number n in order to meet a required accuracy for a given point x. At some point in this
file, you should call (调用) the function in sine.m explicitly.
(3) Write a third M-file named “plotGraphs.m” which has a function taking the n as input and
plots both sin(x)-x and sine(x,n)-x on the same graph. The variable x should take the
values from -2π to 2π with the step length less than 0.1. Remember to add title, labels and
legend to the graph properly. Call this function from the function in computeN.m, so that
each time computeN(x,δ1) is executed, a graph of the two curves is plotted.
Hint: You may need to slightly (稍微地) change the function in sine.m to make it adapts
the cases that x is a vector.
(4) Run computeN(2, 10e-6) in the command window of Matlab and observe the difference
between the two curves: sin(x)-x and sine(x,n)-x.

这个也太简单了吧,  

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引用第4楼negative于2008-01-07 20:35发表的  :

蝈蝈给做一个嘛。。。我数学实验算是白学了。。。

偶在清水河,看不到你的那个图是啥子...

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引用第6楼woofuzhe于2008-01-07 20:37发表的  :
是要得到  泰勒级数  吗？

是让你把一个数字的正弦函数用泰勒级数的n次展开,其中n是给定的,这个数字也是给定的,后面再比较它了matlab里面的sin函数的值的差

忘记n!的函数了,可否告知

告知一下那个函数名三

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引用第7楼negative于2008-01-07 20:39发表的  :
我晕。。。。
sin(x)=求和k从1到年n,(-1)^(k-1)*x^(2k-1)/(2k-1)!
能看懂否？

这个公式是错的吧?试一个,sine(2,1)都已经大于1了

function y=sine(x,n)
if n<1
    error('input error! n should be positive!')
    return;
else
    y=0;
    for k=0:n
        y=y+(-1)^(k)*(x)^(2*k+1)/(gamma(2*k+2));
    end
end

把那个文件保存了就行了,保存时不要改名字,直接在command里面输入就行,比如:sine(3,6)

我刚才写的那个是用书上的那个展开式哈,你把它带进去就行了,如果你要用你那个就对照着改一下吧

不要给我FY哈,我用不到

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引用第40楼starroamer于2008-01-07 21:28发表的  :
给我吧，我用得到

可怜我在清水呀,要是在RX就好了

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引用第42楼starroamer于2008-01-07 21:37发表的  :

等你真的到RX了你也许就不这么想了……

在RX了四年.............................