pllllllllllllZzz ..... I need it today ;(

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mon mon 2011-10-26

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*Hi evry body :)

can U help me to answer qustion num(c)? I don't Know how can i answer it :( PlZz help me =,(*

Exercise 2:

(a) Write an m-file named cosmx.m (“COS Minus X”) that defines the function:

(x) = cos x - x

Recall that a function m-file is one that starts with the word function. In this case it should start off as

function y = cosmx ( x )
% y = cosmx(x) computes the difference y=cos(x)-x
% your name and the date
y = ???

(This is very simple(the object of this exercise is to get going.)

(b) Now use your cosmx function to compute cosmx(1). Your result should be about -0.4597.

(c) Now use your cosmx function in the same plot sequence as above to plot cosmx and the horizontal axis on the interval -π < x < π. Hint: The horizontal axis is the line y = 0.

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Daniel Shub 2011-10-26

Great, so show us the function and then show us what you have done for part c.

mon mon 2011-10-26

a)

function y = cosmx ( x )

%y = cosmx(x) computes the difference y=cos(x)-x

% Name & Date

y =cos(x)-x;

end

b) in command window :

cosmx(1)

and it give me the correct result -0.4597

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Answer 1

mon mon 2011-10-26

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plZz help me =,(

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Image Analyst 2011-10-26

How generous of you to accept your own "answer" instead of someone else who helped you.

Daniel Shub 2011-10-26

I think he may have accepted his answer prior to getting any help (with the possible exception of Amardeep's answer). It was accepted before I got involved.

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Answer 2

Daniel Shub 2011-10-26

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ohhh, I know the answer ...

function y = cosmx ( x )
% y = cosmx(x) computes the difference y=cos(x)-x
% your name and the date
y = randn(size(x));
y(x == 1) = -0.4597;

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mon mon 2011-10-26

Thanks Daniel ,

But it give me an Error ,too. =(

Daniel Shub 2011-10-26

@mon mon, you are right, I made a mistake. It should work now.

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Answer 3

Amardeep 2011-10-26

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Create a function which calls cosmx which should look something like. I have left out the plotting functions and the variable arraying to create plottable data.

x = -pi
while x=< pi
y=cosmx(x)
x=x+0.01 (or whatever division resolution you want along the x axis)
end

That should be more than enough to get you along the right lines for part c.

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mon mon 2011-10-26

thanXx Amardeep =)

but it give me ERROR =(

Sean de Wolski 2011-10-26

<=

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Answer 4

mon mon 2011-10-26

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my Answer in part (a)

function y = cosmx ( x )
%y = cosmx(x) computes the difference y=cos(x)-x
%  Name & Date
y =cos(x)-x;
end

Then part (b) I wrote in command window cosmx(1)

It give me correct >>>> -0.4597

but I do not know part(c) =(

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Daniel Shub 2011-10-26

If I asked you to evaluate cosmx at -pi, 0, and pi, how would you do that. What about if I asked you to evaluate cosmx between -pi and pi with steps of 0.01. Do you know how to plot anything?

try

doc plot

mon mon 2011-10-26