Question

1.1 la puterea 1×1.1 la puterea 2×...×1.1 la puterea n=1.21 la puterea 105 n=? Repede dau coronita

Answer 1

1,1^ (1+2+....+n) =(1,1²)^105

n(n+1)/2=210
n(n+1)=420=20*21
n=20 verifica
n(n+1) crescatoare pt n>1 , deci n=20 solutie unica