# Calc 3

posted by
**Samantha**
.

How do I integrate rcos2theta dr? and then I have to plug in the limits 1 and 2sin2theta for theta and plug what I get from that into a second integral. Help!

posted by
**Samantha**
.

How do I integrate rcos2theta dr? and then I have to plug in the limits 1 and 2sin2theta for theta and plug what I get from that into a second integral. Help!