11The reason I posted it here was that some guy in mathlinks used an useful substtituiton of putting x as tanθ...but my query is why such a substitution - I mean what hinted at that?
Solve for positive reals (x,y,z)
z^2+2xyz=1
3x^2y^2+3y^2x=1+x^3y^4
z+zy^4+4y^3=4y+6y^2z
It's been a while no -one has really given any elaborate soln for this.....
-
UP 0 DOWN 0 0 2
2 Answers
11
62The hint of such a substitution comes from equation 2...
which is also a quadratic in y2
Think of the formula of tan 3k... specially in the second equation..