Integration differential

[remslie]

Hi,

I am trying to solve the following double integral equation in Mathcad (Equation 17 extracted from tech paper).

I get an "a name is required here" error when using the d(sin(q)2) i.e "d sine squared" in the differential. Can I use this d(sin(q)2)? Is there a trick to getting the syntax correct? Many Thanks Ross

[terryhendicott]

Hi,

Mathcad is telling you it needs the name of a function.

set a function name before differentiation.  sin_f(theta):=sin(theta)^2

use this name in the differentiation.

It helps if you attach the file to the post.

Cheers

[Werner_E]

> Can I use this d(sin(q)2)? 

Unfortunately no.

Mathcad does not support functions here, just variables.

So you have to manually evaluate the differential yourself  d(sin(q)^2)=2*sin(q)*cos(q) dq and use this instead.

[VladimirN]

There is no attachment in your message.

[Werner_E · Accepted solution]

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@VladimirN wrote:

There is no attachment in your message.

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I guess we can consider the question as answered.

The same question was asked a second time, but with an attachment -> https://community.ptc.com/t5/PTC-Mathcad/Double-Integration-error-with-sin-squared-differential/td-p/661132/jump-to/first-unread-message

[remslie]

Vladimir, Werner,

 Apologies for omitting the attachment in the first post.Thank you for your efforts. I now have my calculation sheet working😀. Regards Ross