# Finding real part of an expression.

by MathematicalPhysicist
Tags: expression, real
 P: 3,243 Hi, I have the next expression: $$\frac{iw+3}{(iw-3)(iw+6)(iw+1)}$$ Now I want to find the real part of this expression via mathematica or maple, and for the love of god it doesn't work, what have I done wrong here?! the codes and their errors are in the attachments. http://oi50.tinypic.com/25zs684.jpg http://oi50.tinypic.com/24wfqt3.jpg Peace out! N.B w is real parameter.
 PF Gold P: 471 Finding real part of an expression. What about "ComplexExpand"? ((Mathematica)) ComplexExpand[(I w + 3)/((I w - 3) (I w + 6) (I w + 1))] $$-\frac{27 w^2}{\left(w^2+1\right) \left(w^2+9\right) \left(w^2+36\right)}-\frac{54}{\left(w^2+1\right) \left(w^2+9\right) \left(w^2+36\right)}-\frac{w^4}{\left(w^2+1\right) \left(w^2+9\right) \left(w^2+36\right)}\\+i \left(\frac{27 w}{\left(w^2+1\right) \left(w^2+9\right) \left(w^2+36\right)}-\frac{w^3}{\left(w^2+1\right) \left(w^2+9\right) \left(w^2+36\right)}\right)$$