Help to solve an integral to find the unknown limit

[Pyros1111]

Hi all,

looking for some help to solve the following equation (circled in red) to find one of the limits of integration (b).

R.d is the other limit of integration which is fixed and known.

The angles 'alpha' and 'beta' are known and fixed.

w is known and fixed, q is known and fixed. 

Angle 'theta' varies with r and b.

Any help would be appreciatred - currently trying to do it in mathcad 15 but i also have access to prime 

[LucMeekes]

Please post your worksheet. Not just a picture!
If possible save it as Mathcad 11 .mcd file. Don't mind the warnings, if any.

Success!
Luc

[Pyros1111]

Hi Luc,

i have attached the calc I have so far. I have also included the paper it comes from, i'm essentially trying to use the derived equation that is the crux of the paper (equation 3.40 on page 77) but struggling to do this in Mathcad. Also included a diagram from the paper to help illustrate where some of the variables come from.

[Pyros1111]

sorry 'q' is also a known and variable - missing from the Mathcad i posted originally but included in this one.

[ValeryOchkov]

[LucMeekes]

I noticed that.

Luc

[LucMeekes]

I think you should check the equations and the known values.

Success!
Luc

[Pyros1111]

Hi Luc,

thanks for this - q will actually be a much smaller value than 300 (error on my part) something more like 1*10^-5 is appropriate in fact. 

Only thing is when i open Mathcad file you attached it doesn't seem to work properly - no plot etc... is this because i am running Mathcad 15?

[Werner_E]

---

Only thing is when i open Mathcad file you attached it doesn't seem to work properly - no plot etc... is this because i am running Mathcad 15?

---

NO, its because Luc usually turns off autocalculation in his sheets. So you may turn it on or manually recalculate the sheet.

[LucMeekes]

That makes it simple to solve numerically. Note that you probably will not find a symbolic solution.

Success!
Luc