Changes

*This function gives the CIS value.

*This function gives the CIS value.

*CIS  is another name for the complex exponential.  

*CIS  is another name for the complex exponential.  

*<math>Cis(x)=e^{ix}=Cosx+i Sinx</math>, where <math>Cos</math> is the <math>Cosine</math> function,<math>i</math> is the imaginary unit and <math>Sin</math> is the <math>Sine</math>.  

*<math>Cis(x)=e^{ix}=Cosx+i Sinx</math>, where <math>Cos</math> is the <math>Cosine</math> function,<math>i</math> is the imaginary unit and <math>Sin</math> is the <math>Sine</math> function.  

*Also <math> Cos(x)= \frac{e^{ix}+e^{-ix}}{2}</math>;

*Also <math> Cos(x)= \frac{e^{ix}+e^{-ix}}{2}</math>;

* <math>Sin(x)=\frac{e^{ix}-e^{-ix}}{2i}</math>  and  <math>i^2</math>=-1.

* <math>Sin(x)=\frac{e^{ix}-e^{-ix}}{2i}</math>  and  <math>i^2</math>=-1.

*So <math>Cis</math> abbreviates <math>Cos + i Sin</math>.

*So <math>Cis</math> abbreviates <math>Cos + i Sin</math>.