Răspuns :
Răspuns:
a -1/a=3 Ridici la patrat
(a -1/a)^2= 9
a^2 -2*a*1/a +1/a2=9
a^2 -2 +1/a2=9 aduni 2 la ambii membrii
a^2 +1/a2=9 +2
Adica exact ce vrei tu sa demonstrezi
(a-1/a)^2=3^2
(a-1/a)^2=9
a^2-2a*1/a+1/a^2=9
a^2-2+1/a^2=9
a^2+1/a^2=9+2
a^2+1/a^2=11
a^2=11 e numar neul
(a-1/a)^2=9
a^2-2a*1/a+1/a^2=9
a^2-2+1/a^2=9
a^2+1/a^2=9+2
a^2+1/a^2=11
a^2=11 e numar neul