SharePoint FBA and windows authentication needs Trust Relationship between domains?

Question

We have SharePoint configured on a domain, Domain1 where FBA is implemented to get users authenticated from Domain1. Now we have another domain, Domain2 which holds the other users that needs to get authenticated from same SharePoint using Windows Authentication. I have three questions,

1. Is this possible to authenticate users from a second domain using Windows Authentication?
2. Do both domains, Domain1 and Domain2 needs establish trust relationship with each other?
3. Do SharePoint needs to establish any kind of trust relationship with the second domain?

I would appreciate if a link to Microsoft's article or a implementation steps is provided for a concrete answer to these questions.

Answer 1

1. It is possible to configure Active directory with multiple domains in SharePoint server. You can achieve this via adding building trust relationship between two domains. Please take a reference to this article: How to Add Trust Domains in a SharePoint Farm

2. Yes, you need to establish trust relationship between two domains.

3. No, trust relationship between two domains is enough.