Writing a sin function program dealing with factorials, help in editing and error?
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I am trying to write a specific program involving the sine function and factorials.
The problem states that:
sin(x) = x - x^3 / 3! + x^5 / 5! - x^7 / 7! + x^9 / 9!
I am trying to get the error rate very low, basically having the number of terms it takes to get enough accuracy by 10^-5, so that:
abs[sin(x) - sk(x)] / abs[sin(x)] = 10^-5
I know the sk equation should be written as:
sk = x-x^3 / 3! + .......x^(2k-1) / (2k-1)!
I am starting out my program with:
for s = 1: maxs
nsteps(s) = (ones(s)
end
I am confused on how to add on to my code to create my desired result, I know intuitively that when plotting this, the #'s should increase as x increases.
[Merged information from duplicate question]
I am trying to write a specific program involving the sine function and factorials.
The problem states that:
sin(x) = x - x^3 / 3! + x^5 / 5! - x^7 / 7! + x^9 / 9!
I am trying to get the error rate very low, basically having the number of terms it takes to get enough accuracy by 10^-5, so that:
abs[sin(x) - sk(x)] / abs[sin(x)] = 10^-5
I know the sk equation should be written as:
sk = x-x^3 / 3! + .......x^(2k-1) / (2k-1)!
I am starting out my program with:
for s = 1: maxs
nsteps(s) = (ones(s)
end
I am confused on how to add on to my code to create my desired result, I know intuitively that when plotting this, the #'s should increase as x increases.
Here is my code:
function [s] = fact(t)
s = 1:max(s);
for s = 1:max(s)
nsteps(s) = ones(s);
end
for t = (1:2:2*k-1);
(-1)^(0:k-1) .* x^t ./ factorial(t);
end
I receive this error when performing it:
??? Undefined function or variable 's'.
??? Undefined function or variable "s".
Error in ==> fact at 2
s = 1:max(s);
HELP PLEASE!
1 comentario
Walter Roberson
el 23 de Abr. de 2012
Elige pointed out that "s" has not been defined in the new code.
Respuestas (2)
Walter Roberson
el 23 de Abr. de 2012
t = (1:2:2*k-1);
(-1).^(0:k-1) .* x.^t ./ factorial(t)
Or something like that.
(Note: corrected -- ^ operators had to be .^ )
7 comentarios
Walter Roberson
el 23 de Abr. de 2012
"=" is not permitted in a "while". "while" has to be given a logical test.
Warning: You initialize s to 0, so max(s) is 0, and 1:0 is the empty vector, so your "for" loop will not do any iterations.
What is the purpose of your nsteps vector? Why are you trying to initialize it to a square matrix such as
1 1 1
1 1 1
1 1 1
(i.e., ones(3))
Richard Brown
el 23 de Abr. de 2012
I take it this is a programming exercise, not a straight mathematics question - you can work out the number of terms pretty easily using Taylor's theorem with remainder ...
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