Why do orbital equations and energy conservation give different answers?

[JaDi13]

I have been going through problems in my textbook and have a question.
The chapter is on gravitation and orbital mechanics. When answering the problems I seem to head towards different methods than what the book prescribes. My answers, primarily using known orbital equations, are close, but not quite the answers the book has in the back. Using the solution guide from Chegg, I find that they often use the conservation of mechanical energy to find answers the book more readily agrees with.
Is one way more correct than the other?
thanks​

 

[Andrew Mason]

Hi JaDi13. Welcome to PF!

It is rather difficult for us to understand what the problem is from what you have posted. If you could provide us with an example of a problem and show us your approach and the textbook solution we could probably help you.

AM

 

[anorlunda]

When you provide more details as @Andrew Mason asked, please include your numerical methods. For example, numerical integration.