Hi, In UML, Requirement Analysis is done by 2 models, 1.Use Case Diagrams and 2.Activity Diagrams.
These 2 models represent the analysis of the requirement by representing the requirements diagramatically. After making these 2 models you analyse the requirements by considering points like..
1. All the requirements covered or not?
2. All the requirements understood or not?
3. Who all are going to use the system(actors)?
4. What all activities will be done.
5. Which actor will perform what activity.
6. What is the sequence of these activities?
7. Do these activities cover all the requirements or not?
etc. etc.

These 2 models generally are shared with the customer who further gives his feedback with reference to his requirements. Regards