Why does Re[] not simplify a fraction with imaginary units in Mathematica?

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member 428835
Hi PF!

I have some variables that are all real, and I have a few ##i##s, all in a fraction. When I ask Mathematica to give me the real part of the entire fraction, ##Re[]##, it simply echoes my input, not giving me anything useful. Any help is greatly appreciated.
 

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You could try using ComplexExpand:
MM.png
 

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phyzguy said:
You could try using ComplexExpand:
View attachment 221008
Yea I've tried this before. I should have been more specific: see what I want is the real component without any imaginary numbers. Like multiplying by the conjugate and simplifying. Do you know if there a built in function that does this?
 
joshmccraney said:
Yea I've tried this before. I should have been more specific: see what I want is the real component without any imaginary numbers. Like multiplying by the conjugate and simplifying. Do you know if there a built in function that does this?

Look again at my post. That's what ComplexExpand does. There are no "i's" in the final answer.
 
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phyzguy said:
Look again at my post. That's what ComplexExpand does. There are no "i's" in the final answer.
Ohhhhh shooot, sorry! I saw the variable ##\lambda i## and thought there was an ##i## in the solution. Sorry and thanks!