Tom Karzes pointed out that this can just be regarded as a difference of squares. But Rohan was on a Gaussian integers binge, so I thought maybe he'd found something rational. His plotting hint was unenlightening until I tried ContourPlot. gosper.org/homer.png . Is it possible those Simpsonian eyes are perfect circles? On the 0 contour? Clipping the Plot3D at 0, gosper.org/homer2.png , suggesting the easily confirmed factorization into two circles. Thankfully, before unmasking Rohan's 3rd hint. --rwg (I don't know what he was plotting with. He says his Mathematica license ran out.) On Sun, Aug 27, 2017 at 2:19 PM, Bill Gosper <billgosper@gmail.com> wrote:
Since braindead xmission.com will doubtless unmask Rohan's shaded hints, I'll just StringReverse them. ---------- Forwarded message ---------- From: Bill Gosper <billgosper@gmail.com> Date: Sun, Aug 27, 2017 at 1:51 PM Subject: Fwd: Factoring challenge To: ..., mathfuneavesdroppers@googlegroups.com, ...
Rohan occasionally composes cryptically worded puzzles. The hard part is usually to find a sensible interpretation of his problem statement (and hints). He just sent me this atypically satisfying one. I'll add a hint of my own: If you see Homer Simpson, you're on the right track!
---------- Forwarded message ---------- From: Rohan Ridenour <catisfluffy@hladkyschool.org> Date: Sat, Aug 26, 2017 at 8:16 PM Subject: Factoring challenge To: Bill Gosper <billgosper@gmail.com>
x^4+2x^2y^2+y^4-5x^2 Hint: ".scitardauq owt otni srotcaf tI" Doublehint: .ti gnittolp yrT Triplehint: .uoy fo retteb detcepxe I [Just unmasked, pleased to say!-] Fun fact: ".y,x htiw 2^y,2^x ecalper uoy fi rotcaf t'nseod tI" ________ --rwg