設(shè)函數(shù)f(x)=logax(a>0且a≠1),若f(x1x2x3)=8,則f(x21)+f(x22)+f(x32)=_.
設(shè)函數(shù)f(x)=log
ax(a>0且a≠1),若f(x
1x
2x
3)=8,則
f()+f()+f(x32)=______.
優(yōu)質(zhì)解答
∵f(x)=log
ax且f(x
1x
2x
3)=8
∴l(xiāng)og
a(x
1x
2x
3)=8
又
f()+f()+f(x32)=
loga(x12)+loga(x22)+loga(x32)=
2[loga(x1) +loga(x2) +loga(x3) ]=2[log
a(x
1?x
2?x
3]=2log
a(x
1x
2x
3)=2×8=16
故答案為:16
我來(lái)回答
類(lèi)似推薦