This is acceptable if you can make your question reasonably self-contained.
That is, for example:
Your actual question could be how to calculate an integral, and this integral should be included in the post.
Your context could be that this integral shows up in a paper your are studying and you link to the paper for further context and mention the specific point where it occurs.
What you should not do is ask a question that only says 'How to obtain equations 12.2 and 12.4 in {some paper}.' or even worse 'How to obtain the integral in {some paper}.'
Also, strive to make the question not too broad. If you have questions about several integrals start with one and see how it goes. If needed, you can then ask a second question.
Finally, it could be useful to mention something about your mathematical background so that persons answering can decide more easily what should be the appropriate level of the answers.