Simplifying symbolically an equation keeping pi (Mathcad 15)

[ClaudioPedrazzi]

Hi everyone,

I have an equation that I would like to let Mathcad simplify for me.  It looks like this:

ok 🙂 I know I could simplify it myself, but please consider this an example!

If I select the left side and then Symbolics > Simplify I obtain the highly unsatisfying result:

what I would like is that pi remains expressed as pi!

I have tried, remembering another thread, the "symbolic undefine" pi:=pi (above the equation) but apparently it does not work!

Am I asking Mathcad 15 too much?  

thanks for any suggestion!

Best regards, Claudio

PS: no, I do not use Prime 😉

PS2: the equation is derived with some manipulation from ASME Boiler and Pressure Vessel Code, Section III, and is related to the allowable stress in a pipe product, under known inner pressure and external moments, at design condition.

[VladimirN]

 Hi Claudio,

Please upload your Mathcad worksheet.

[AlanStevens · Accepted solution]

Try replacing the 1.5 by 3/2

[ClaudioPedrazzi]

Hey, thanks @AlanStevens it works!  I do not understand why, but it works 🙂

I also had the thought with fractions and also tried "Format > Result > Fraction" but it gave ugly fractional approximations of the numbers shown above!

[Werner_E]

It works because the symbolic engine has a nasty "feature". Whenever it encounters a decimal point it switches to some kind of float/approximation mode (similar to what you achieve if you add "float,20".