Question

Aflati ultima cifra a numarului 2la puterea 2010. Repede

Answer 1

$u(2^{4k}) = 6$

2010 = 2008 + 2 = 4k+2

$u(2^{4k+2})=4$

Deci:

$u(2^{2010}) = 4$

Answer 2

2^1=2;2^2=4;2^3=8;2^4=16;2^5=32-cifra 2 se repeta a 4 oara
2010/4=502rest2
2^2=4
ultima cifra=4