# Finding the area enclosed by r=3sin theta

by grog
Tags: area, polar coordinates
 P: 23 1. The problem statement, all variables and given/known data Find the area enclosed inside r=3 sin (theta) 2. Relevant equations integral? 3. The attempt at a solution basically, I took $$\int3sin\Theta$$ from 0 to 2pi, then pulled the 3 out to get $$3\int sin\Theta$$ from 0 to 2pi and then $$3[-cos(\Theta)]$$ evaluated from 0 to 2pi. that seems too easy. what am I missing?
 Sci Advisor HW Helper Thanks P: 25,243 Who said everything has to be super hard? But if you work that out, you'll get 0 for the area. Is that right? It might help to draw a picture. And, hey, area in polar coordinates isn't the integral of r dtheta, is it? Would you look up the right formula for area?
 P: 23 ah. that's what it was. I forgot about the formula for area. : ( Thanks!
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Finding the area enclosed by r=3sin theta

 Quote by Dick Who said everything has to be super hard? But if you work that out, you'll get 0 for the area. Is that right? It might help to draw a picture. And, hey, area in polar coordinates isn't the integral of r dtheta, is it?
Well, actually, Dick, area in polar coordinates is r dtheta! You didn't say quite what you meant to, did you?

 Would you look up the right formula for area?