# How to simplify an expression....

Posted 9 years ago
3859 Views
|
2 Replies
|
0 Total Likes
|
 Hello,I have an expression: vo=(aol id Rf) / (1 + aol + C Rf s). i define beta = 1/(s*C*Rf) I'd like to simplify the expression by dividing top and bottom by aol, and then substituting beta for 1/(sCRf). I divided the numerator and denominator by aol by separating numerator and denominator using Numerator and Denominator instructions and carrying out the division. However, I'm stuck on how to substitute beta for the expression 1/(sCRf) in the equation.What I'm ultimately trying to get to is for Mathematica to return: vo=1/(1+1/(aol*beta)) from the original expression above.thanks for the help. Jorge
2 Replies
Sort By:
Posted 9 years ago
 thanks for the clues....here's what I did based on your input: In:= vo = (vo /. sol3[]) // Simplify Out= (aol id Rf)/(1 + aol + C Rf s) In:= num = Numerator[vo]/aol Out= id Rf In:= den = Denominator[vo]/aol Out= (1 + aol + C Rf s)/aol In:= den = Apart[Expand[den /. {1 + C Rf s -> 1/beta} // Simplify]] Out= 1 + 1/(aol beta) In:= vo = num/den Out= (id Rf)/(1 + 1/(aol beta)) thank you.
Posted 9 years ago
 Do you mean this:  In:= vo = (aol id Rf)/(1 + aol + C Rf s) Out= (aol id Rf)/(1 + aol + C Rf s) In:= % /. {C Rf s -> beta} Out= (aol id Rf)/(1 + aol + beta) There may be other ways as well, but that gets beta substituted in.