Question Number 194781 by MM42 last updated on 15/Jul/23
$${f}_{{n}\:} \:\:{the}\:{general}\:{sentence}\:{is}\:{seqiencee} \\ $$$${fibonacci}.\: \\ $$$${prove}\:{that}\::\:\:{f}_{\mathrm{2}{n}ā\mathrm{1}} ={f}_{{n}} ^{\mathrm{2}} +{f}_{{n}ā\mathrm{1}} ^{\mathrm{2}} \\ $$$$ \\ $$