Why can't I get an output when I am trying to find Cosine of 180 radians using Taylor series expansion.

sum= double(1);
sign=1;

for n=2:2:1000

      sign = -sign;

      form = ((Rad).^n)/factorial(n);
      sum = sum + (sign*(form));

      if form <= 0.000000001
          break;
      end

end
CosFormula = sum

[Naty S]

Could you please clarify what you are trying to do? The code runs and and the CosFormula variable has a the expected value. Are you trying to use it as a function?

[Torsten]

"Rad" is undefined.

Furthermore, you should not build x^n/n! anew in each step because you will arrive at Infinity/Infinity quite soon for Rad>1. Note that form_new = form_old*x^2/((2*n-1)*2*n).

What are you trying to calculate - cos(180) or cos(pi) ? Note that the argument in the Taylor series expansion is in radians, not in degrees.

Best wishes

Torsten.

[Guillaume]

Do not use sum or sign as variable names. They both are the names of frequently used matlab functions and having a variable with the same name means you can't use the functions anymore.