F(x,y) = x^3 - y^3 - 2xy + 6
the critical points i obtained are (0,0), (2/3,2/3) and (2/3, -2/3), but the solution for the critical points are (0,0) and (-2/3,2/3). did i made any mistake somewhr?

Question

anonymous · Answer

*solution gvs (0,0) and (-2/3,2/3)

anonymous · Answer

mayb i should provide my workings also?

experimentx · Answer

Must be some calculation error http://www.wolframalpha.com/input/?i=3x%5E2+-+2y+%3D+0%3B+-3y%5E2+-+2x+%3D+0

anonymous · Answer

omg.. now i see it. LOL

anonymous · Answer

its the diff wrt y, missed out the - ._.

anonymous · Answer

sry for the fuss

anonymous · Answer

erm, so when$$x=-\frac{2}{3},$$$$y ^{2}=-\frac{2}{3}(-\frac{2}{3})$$why y=2/3 only?

anonymous · Answer

shouldnt it be + - ?

anonymous · Answer

@arnab09 whats your opinion on the y=2/3 only?