How to plot this function

(U0/d4)(x^4−2*x^2*d^2 + d^4) tried different codes but I can't make it work

[Ameer Hamza]

Can you describe the notation?

[David Hill]

what ranges for your variables? Are both d and x variables? Do you want a 3D plot? Is U0 and d4 constants?

[Daniel Skoglund]

d is a known lenght, x is the position and u is a known constant. I do not know the values of d,u and x as it is not specified

[Daniel Skoglund]

The question is Make an energy diagram. Find the equilibrium points, mark these on the diagram and characterize their stability.