数列﹛an﹜满足a1=3,an=√an-1(n≥2),则log3(a1•a2•···an)=…数列﹛an﹜满足a1=3,an=√an-1(n≥2),则log3(a1•a2•···an)=………?

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数列﹛an﹜满足a1=3,an=√an-1(n≥2),则log3(a1•a2•···an)=…数列﹛an﹜满足a1=3,an=√an-1(n≥2),则log3(a1•a2•···an)=………?
数列﹛an﹜满足a1=3,an=√an-1(n≥2),则log3(a1•a2•···an)=…
数列﹛an﹜满足a1=3,an=√an-1(n≥2),则log3(a1•a2•···an)=………?

数列﹛an﹜满足a1=3,an=√an-1(n≥2),则log3(a1•a2•···an)=…数列﹛an﹜满足a1=3,an=√an-1(n≥2),则log3(a1•a2•···an)=………?
an =√(a(n-1)
logan = (1/2)loga(n-1)
{logan} 是等比数列,q=1/2
logan = (1/2)^(n-1) .(loga1)
= (1/2)^(n-1)
log(a1.a2.an)
=loga1+loga2+...+logan
=1+1/2+.+(1/2)^(n-1)
= 2[1-(1/2)^n]