Question

Daca a=(2+rad3)la patrat -rad2(rad5-rad3)-2rad3(2-rad2)+rad2(rad5-rad3)
Aratati ca a ∈ lui N.

Answer 1

a=(2+√3)²-√2(√5-√3)-2√3(2-√2)+√2(√5-√3), ∈ N

=4+4√3+3-(√10-√6)-(4√3-2√6)+√10-√6 

=4+4√3+3-√10+√6-4√3+2√6+√10-√6  

=7∈N