Question Number 130102 by mohammad17 last updated on 22/Jan/21
$${if}\:{U}\left({x},{y}\right)=\mathrm{2}{x}−{x}^{\mathrm{3}} +\mathrm{3}{xy}^{\mathrm{2}} \:{construct}\:{a}\:{complex}\: \\ $$$${analytical}\:{function},\:{the}\:{expression} \\ $$$${of}\:{which}\:{is}\:{the}\:{true}\:{part}\: \\ $$