已知log52=a,log53=b,用a.b表示log524
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因为a−c=(3−k,−1),所以(a−c)•b=0(3-k,-1)•(1,3)=3-k-3=0所以k=0故答案为:0
根据函数单调性,(lg23)^x-(lg53)^x是减函数,所以x>-y
因为a3关于原点对称,则-(a-1)>1-(-a+3)
2log52<1,1<(12)−0.8=20.8<211,∴a<c<b.故选:B.
∵a+1a=10,∴(a+1a)2=10,∴(a-1a)2+4=10,∴a-1a=±6.
∵已知a=log23+log23=log233=log227>1,b=log29-log23=log293=log227>1,c=log32<1,∴a=b>c,故答案为a=b>c.
②A,B互为相反数正确(2分)∵B=1x+1−1x−1(3分)=x−1(x+1)(x−1)−x+1(x+1)(x−1)(4分)=(x−1)−(x+1)(x+1)(x−1)(5分)=−2x2−1=-A∴
∵a+1a=5,∴(a+1a)2=25,即a2+2+1a2=25,∴a2+1a2=23,a4+a2+1a2=a2+1+1a2=23+1=24.故答案为:24.
√[4-(a+1/a)²]-√[4-(a-1/a)²]=√[4-(a²+2+1/a²)]-√[4-(a-1/a)²]=√[-(a²-2+1/
a>c>0>d>b绝对正确,我推算过了
原式=a2+6a-2-6a+2a2=3a2-2,当a=-13时,原式=3×(-13)2-2=3×19-2=-123.
log53+log51/3=log53-log53=01/3=3^(-1)
∵|a|a+b|b|=0,∴a、b异号,故|a×b|a×b=-1.
∵a∥b,∴m+4=0∴m=-4故答案为:-4
∵A=m−nm+n+3是m+n+3的算术平方根,∴m-n=2,∵B=m−2n+3m+2n是m+2n的立方根,∴m-2n+3=3,∴联立得到方程组m−n=2m−2n+3=3解这个方程组得:m=4,n=2
(1)-(2)得,x=a2-2a,∴a2-2a=3,解得a1=-1,a2=3.将a1=-1,x=3代入(2)得3+y=-2,y=-5,即m1=-5;将a2=3,x=3代入(2)得3+y=2×3,y=0
y=log52底数呢?再问:y=log52,即5^y=2再答:z=e-1/2e^1/2<2,∴z=e-1/2>1/25^y=2;y<1/2
∵1=log33>a=log32>log31=0,b=log52<log32=a,c=log23>log22=1,∴c>a>b.故答案为:c>a>b.
已知A=a-1a+3b是a+3b的算术平方根,B=2a-b-11-a2是1-a2的立方根,a-1=22a-b-1=3,a=3b=2,A=a+3b=3+3×2=3,B=31-a2=31-32=-2A+B