Solve for a variable in an equation

[SFares]

Hello,

please scroll down to the red arrow in the attached sheet. i have been able to solve for Pu, using solve. but the issue is i have no control over the number of decimal places, the unit, and be able to use the result for Pu in subsequent calculations. Are there other ways to be able to do this? Thanks!

[Werner_E · Accepted solution]

• Follow the symbolic evaluation by a numerical one in the same region

• Assign the result of solve to a variable and evaluate it numerically.

• Probably the best as all you want is a numerical solution anyway: Use a solve block with find().

The attached sheet should help.

PS: Keep you files nice,tight and small by deleting sections and especially pics which are not essential for the question before attaching.

[SFares]

Hello Werner,

In regard to following the symbolic evaluation by a numerical one in the same region, i am not sure how to do that.

when i type Pu below the line of symbolic evaluation, i don tget the same equal sign you have(=), i get( :=). which one do i use? i like the first method b/c it is simple. Thanks!

[Werner_E]

In regard to following the symbolic evaluation by a numerical one in the same region, i am not sure how to do that.

You simply somewhere in the region and type =

when i type Pu below the line of symbolic evaluation, i don tget the same equal sign you have(=), i get( :=). which one do i use? i like the first method b/c it is simple. Thanks!

This probably means the variable you typed is not defined.

You use a normal equal sign (numeric evaluation) but probably you typed a wrong variable name. I used the same as you used in your formulas P.u (literal subscript!).

[SFares]

yes, i saw what you did where you assigned it to a variable first. Thanks!

i posted very similar issue but i am not sure why i got strange results. for (e wall). it should be in inches or feet.

[SFares]

i was able to figure out the issue.

[MikeArmstrong]

Would you please post the solution to help others.