Question #90b3f

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Answer 1 · 2017-02-27T21:22:49

$y = pm sqrt(25 - 10x)$

Assuming you mean:

$r = 5/(1 + cos theta)$

Then we know the following:

$x = r cos theta implies cos theta = x/r$
$y = r sin theta$
$r = sqrt(x^2 +y^2)$

So we pick 'n' mix:

$sqrt(x^2 +y^2) = 5/(1 + x/sqrt(x^2 +y^2) )$

Cross - multiply:

$sqrt(x^2 +y^2) + x = 5$

$sqrt(x^2 +y^2) = 5 - x$

$x^2 +y^2 = (5 - x)^2$

$y^2 = (5 - x)^2 - x^2$

$y = pm sqrt(25 - 10x)$