I'm trying to display a graphic that is conditional based on whether a certain number of events have occured during the past calendar year. The logic is as follows - if someone has attended more than 2 occasions in the past 12 months, display a smiley face. If not, display a frowny face. I can get this to work without the date parameters but I can't figure out how to limit the formula to assessing just the past 12 months from the current day. Any suggestions would be very much appreciated!

Here is what I've got so far:

IF(Total_Occasions_Attended__c >2, TODAY() - Date_of_Last_Participation__c),
IMAGE("/servlet/servlet.FileDownload?file=015f00000005Qgv", "Happy", 16, 16),
IF(Total_Occasions_Attended__c <3,TODAY() - Date_of_Last_Participation__c ),
IMAGE ("/servlet/servlet.FileDownload?file=015f00000005QhP", "Sad", 16, 16),NULL))

I keep getting this error:

Error: Syntax error. Extra ','

I'm a new admin trying to get my feel wet writing workflow formulas. I'm not sure if this is what I need or if I'll need a trigger instead. I'd like a checkbox to update on the Contact record when someone becomes attached to a Campaign with a certain record type (i.e. a Campaign Member record is created or deleted). Any suggestions would be incredibly helpful! 

I'm trying to display a graphic that is conditional based on whether a certain number of events have occured during the past calendar year. The logic is as follows - if someone has attended more than 2 occasions in the past 12 months, display a smiley face. If not, display a frowny face. I can get this to work without the date parameters but I can't figure out how to limit the formula to assessing just the past 12 months from the current day. Any suggestions would be very much appreciated!

Here is what I've got so far:

IF(Total_Occasions_Attended__c >2, TODAY() - Date_of_Last_Participation__c),
IMAGE("/servlet/servlet.FileDownload?file=015f00000005Qgv", "Happy", 16, 16),
IF(Total_Occasions_Attended__c <3,TODAY() - Date_of_Last_Participation__c ),
IMAGE ("/servlet/servlet.FileDownload?file=015f00000005QhP", "Sad", 16, 16),NULL))

I keep getting this error:

Error: Syntax error. Extra ','

I'm a new admin trying to get my feel wet writing workflow formulas. I'm not sure if this is what I need or if I'll need a trigger instead. I'd like a checkbox to update on the Contact record when someone becomes attached to a Campaign with a certain record type (i.e. a Campaign Member record is created or deleted). Any suggestions would be incredibly helpful!