area

Find the area bounded by r=a(1+cosθ),0<θ<2π.

13 Answers

62
Lokesh Verma ·

Read this one... this is very very similar

http://targetiit.com/iit_jee_forum/posts/area_931.html

33
Abhishek Priyam ·

just for fun u can see this graph although no relation from finding its area ;)

thats for a>0.... betters say a=1

13
Двҥїяuρ now in medical c ·

3/2Î a2

1
skygirl ·

hmm.. APPLE !!!!!!!!!!!!!!!

11
Anirudh Narayanan ·

Hey, Abhi. Great graph, man. How did you do it? [7]

62
Lokesh Verma ·

r=a(1+cosθ),0<θ<2π.

dA=1/2r2dθ (See the post on the link above for complete explanation..)

Area= ∫1/2a2(1+cosθ)2dθ

= ∫1/2a2(1+2cosθ+cos2θ)dθ

= ∫1/2a2(1+2cosθ+(1+cos2θ)/2)dθ

This should give u the answer when integrating from 0 to 2pi :)

1
skygirl ·

i have a question... is this there in iit syllabus??
jus say -> 'yes' or 'no' . :P

1
greatvishal swami ·

well its a part of polar coordinates (not a part of syllabus:))

but it was not difficult & u hav to study it in 1st year( but then we hav formulas to find it:))

1
skygirl ·

huh! :P
i asked 'yes' or 'no ' :P

1
greatvishal swami ·

i was dead sure of this reaction :D

1
Prashant Shekhar ·

:)

62
Lokesh Verma ·

This is not in syllabus sky..

dont worry about this part :)

even though this makes the solutions at times much simpler.. .like even the most trivial case of finding the area of a circle...

1
skygirl ·

okie..

thank U... :)

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