Hey guys, this is my problem:(adsbygoogle = window.adsbygoogle || []).push({});

find the cartesian equation of the locus:

|z-12i|/|z+36|=3

So far ive got here:

introduce z=x+iy then collect terms gives:

√(x^{2}+(y-12)^{2})=3√((x+36)^{2}+y^{2})

Squaring both sides I get:

x^{2}+(y-12)^{2}=9(x+36)^{2}+9y^{2}

This is where I am stumped... I've tried expanding it to see if I can factorise it into a standard circle, but I havn't been able to find a neat solution. Am I missing a trick here? Any help would be hugely appreciated as It's actually driving me insane!

Thanks

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# Homework Help: Describing a locus

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