The potential energy of a conservative system is given by U=(10x2−4X)J.The equilibrium position is
0.4m
0.2 m
0.1m
0.5m
U=10x2−4xF=−dvdx=−ddx10x2−4xF=−[10×2x−4]=4−20x
For equilibrium position
F=04−20x=0⇒20x=4x=0.2m