yes it will fire the respective trigger and The Document mentions that the Parent record record goes through save procedure meaning the trigger will fire on parent record if there is a modification on the field of child record that feeds to the parent as roll up
It will.
This is documented in step 13 of the triggers and order of execution section of the apex developer's guide:
http://www.salesforce.com/us/developer/docs/apexcode/Content/apex_triggers_order_of_execution.htm
The parent record goes through the full save procedure when the roll up summary is updated.
All Answers
yes it will fire the respective trigger and The Document mentions that the Parent record record goes through save procedure meaning the trigger will fire on parent record if there is a modification on the field of child record that feeds to the parent as roll up
Yes, this will put any records that have a rollup from teh updated record into the update process. Running workflows, triggers, etc...
It will.
This is documented in step 13 of the triggers and order of execution section of the apex developer's guide:
http://www.salesforce.com/us/developer/docs/apexcode/Content/apex_triggers_order_of_execution.htm
The parent record goes through the full save procedure when the roll up summary is updated.