For U(x)=ax⁴−bx² with a,b0, minima occur at:

Question

For U(x)=ax⁴−bx² with a,b>0, minima occur at:

G1 Physics · Accepted Answer

U'=2x(2ax²−b). At x=±√[b/(2a)], U''>0, so these are minima.