how to write a function in interval?

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hi,
can you please help me to write this function code in matlab?
thank you in advance
  2 Comments
José-Luis
José-Luis on 21 Oct 2014
Edited: José-Luis on 21 Oct 2014
What have you tried so far?
I would recommend you to read the "Getting started" part of the documentation.
You might want to look at the fzero() function.
doc fzero
doc plot
doc fplot
lina
lina on 21 Oct 2014
I attached the question in jpg form can't write the code :'(

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Accepted Answer

Matt Tearle
Matt Tearle on 21 Oct 2014
MATLAB Academy can help you learn the basics of MATLAB. Also the Getting Started section of the doc, as Jose-Luis suggested.
For this specific question, you'll need to:
  1. create a vector of x values from -2 to 5.
  2. create a corresponding vector of y values by evaluating the function.
  3. plot y as a function of x.
  4. maybe pretty up the graph a bit.
For 2 you'll need to know about array operations. For 4 you can use xlabel, ylabel, title, xlim, ylim, and/or axis.
As Jose-Luis mentioned, if you need the roots exactly, you can use fzero, but that seems a bit advanced for HW#1. Because the function is a polynomial, you could also use polyval (for part 2) and roots. But, again, that seems more than is necessary.
  5 Comments
lina
lina on 21 Oct 2014
pardon Matt but there is another problem in plotting dimension
x=(-2:5);
y=x.^4-5.*(x.^3)+2.*(x.^2)+6.*(x)-4;
plot(y,[-2,5]);
I get this error ??? Error using ==> plot Vectors must be the same lengths.
what should I do?
thank u in advance
Matt Tearle
Matt Tearle on 22 Oct 2014
You don't need to specify the domain to the plot function, just the x values and their corresponding y values (in that order): plot(x,y)
If you want to adjust the axis limits that MATLAB chooses, use the xlim and/or ylim functions (use the doc to see how they work).

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More Answers (1)

Rupa Kupireddy
Rupa Kupireddy on 8 Feb 2022

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