1.log2(x+1)^2+log4(x+1）= 2log2(x+1)+1/2 log2(x+1) =5/2 log2(x+1) = 5,解得：x=3
2.x^2>=0,x^2+1>=1,log3(x^2+1) >=0
3.對(duì)y進(jìn)行求導(dǎo),得：y' = 2ln2*4^x - 3,令y'>=0,得：x>= log4(3/2ln2)
4.已知y=log2 t的函數(shù)必過(guò) (1,0)點(diǎn),那么令x+3=1,得,x=-2,此時(shí)y=-4,即 必過(guò) (-2,-4)
5.額,題目是否有錯(cuò)?In(x+1)小于1，謝謝這個(gè)很簡(jiǎn)單， lne = 1那麼 ln t 函數(shù)為遞增函數(shù)，那麼 x+10，所以答案為 -1