[tex]a^4+b^4=a^2b^2\\
a^4-a^2b^2+b^4=0\\
a^4-2a^2b^2+b^4+a^2b^2=0\\
(a^2+b^2)^2=-a^2b^2[/tex]
The only possible option is that [tex]a^2+b^2=0 \wedge a^2b^2=0\\[/tex] and this condition is met only when [tex]a=0 \wedge b=0[/tex].
[tex]0^6+0^6=0\\
0=0[/tex]