Question 437605
{{{r^2 = x^2 + y^2}}}, {{{x = rcos(theta)}}}, and {{{y = rsin(theta)}}}.
{{{r^2=2cos^2(theta) + 3sin^2(theta) }}}
<==> {{{r^2 = 2(x/r)^2 + 3(y/r)^2}}}
<==> {{{r^2 = 2x^2/r^2 + 3y^2/r^2}}}
<==> {{{r^4 = 2x^2 +3y^2}}}
<==> {{{(x^2 + y^2)^2 = 2x^2 +3y^2}}}