Question

等比数列求解答等比数列a3×a11＝16.则㏒2a2＋㏒2a12是多少

Answer 1

a(n)=aq^(n-1),

16 = a(3)a(11)=a^2q^(12),

a(2)a(12)=a^2q^(12) = 16.

log_{2}[a(2)] + log_{2}[a(12)] = log_{2}[a(2)a(12)] = log_{2}[16] = 4