(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Show that the cardioid r=a(1+cos(theta)) can be represented by r=2acos^{2}(theta/2), 0<=theta<=2pi (theta is between 0 and 2pi).

2. Relevant equations

3. The attempt at a solution

I'm pretty sure I have to equate the two expressions, but I haven't been able to do this. Then I thought of converting both of them to cartesian form (and seeing if they have the same equation) but that's turning into a bit of a mess. Any guidance would be greatly appreciated!

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# Representing a Cardioid

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