[tex] \nabla f = \lambda \nabla g [/tex]
where f is the function you want to find the extrema of and g is the contraint?
Also how would you identify the above in the following
Determine the least real number M such that the inequality
|ab(a^2-b^2) + bc(b^2-c^2) + ca(c^2-a^2)|\le M(a^2 + b^2 + c^2)^2[/tex]
holds for all real numbers a, b and c.
The Attempt at a Solution
It is the first part of the problem which I cannot do so there is no working to show
You have to minimise M but subject to what? Also, there is no explicit definition for M, only the inequality.