设函数f(x)是函数g(x)=![]() A.[0,+∞) B.(-∞,0] C.[0,2) D.(-2,0] |
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函数f(x)=-![]() ![]() A.在[- ![]() B.在[- ![]() C.在(-∞,0]上为增函数 D.在(-∞,0]上为减函数 |
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函数y=log2(x+1)+1(x>0)的反函数为( ) A.y=2x-1-1(x>1) B.y=2x-1+1(x>1) C.y=2x+1-1(x>0) D.y=2x+1+1(x>0) |
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函数y=-![]() A.y=- ![]() B.y=- ![]() C.y=-x+1(x∈R) D.y=-x-1(x∈R) |
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已知数列{an}满足,![]() (1)令bn=an+1-an,证明:{bn}是等比数列; (2)求{an}的通项公式. |
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已知{an}是等比数列,a2=2,a4=8,则a1a2+a2a3+a3a4+…+anan+1= . | |
已知{an}是公比为常数q的等比数列,若a4,a5+a7,a6成等差数列,则q等于 . | |
在正项数列{an}中,a1=2,点(![]() ![]() ![]() A.2n-1﹡ B.2n+1-2 C.2 ![]() ![]() D.2 ![]() ![]() |
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已知等比数列{an}满足a1+a2=3,a2+a3=6,则a7=( ) A.64 B.81 C.128 D.243 |
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已知等比数列{an}满足an>0,n=1,2,…,且a5•a2n-5=22n(n≥3),则当n≥1时,log2a1+log2a3+…+log2a2n-1=( ) A.(n-1)2 B.n2 C.(n+1)2 D.n2-1 |
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