Ask your own question, for FREE!
Mathematics 21 Online
OpenStudy (anonymous):

i need your help. cartesian to polar conversion..

OpenStudy (anonymous):

\[r^2 \sin^2 \theta = \frac{ r^3\cos^3 \theta }{ 2a - r costheta }\]

OpenStudy (anonymous):

the real equation was y^2 = x^3 / 2a - x

OpenStudy (anonymous):

and i need to derive the answer which is r= 2a sin theta tan theta

OpenStudy (anonymous):

Okay first left side: \[ r^2\sin^2\theta = (r\sin\theta)^2=y^2 \]

OpenStudy (anonymous):

There are four formula to remember: \[ r^2=x^2+y^2\\ \theta = \tan \frac yx\\ x=r\cos\theta\\ y=r\sin\theta\\ \]

OpenStudy (anonymous):

y^2 = x^3 / 2a - x.. i just substituted the rcos theta and rsin theta hehe :)

OpenStudy (anonymous):

okay so square root both sides if you want \(y=f(x)\)

OpenStudy (anonymous):

then...

OpenStudy (anonymous):

the answer of this is r= 2a sin theta tan theta :) i need the process.. im always lost..

OpenStudy (anonymous):

Wait... you started in Cartesian and are going to polar?

OpenStudy (anonymous):

yes

OpenStudy (anonymous):

\[ \begin{split} y^2 &= \frac{x^3}{2a - x}\\ 2ay^2-xy^2&=x^3\\ 2ay^2&=x^3+xy^2\\ 2ay^2&=x(x^2+y^2)\\ 2ar^2\sin^2\theta &=r^3\cos\theta \\ 2a\sin^2\theta &=r\cos\theta \\ r&=2a\tan\theta\sin\theta \end{split} \]

OpenStudy (anonymous):

another equation.. y^2 = x(x-a)^2/ 2a- x..

OpenStudy (anonymous):

the answer is r^2 - 2arsec theta + a^2 = 0.. i dont know how to derive sec

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!