(1)计算:2log32-log3329+log38-25log53.(2)已知x=27,y=64.化简并计算:5x-23y12(-14x-1y12)(-56x

(1)计算:2log32-log3329+log38-25log53.(2)已知x=27,y=64.化简并计算:5x-23y12(-14x-1y12)(-56x

题型:解答题难度:一般来源:不详
(1)计算:2log32-log3
32
9
+log38-25log53
(2)已知x=27,y=64.化简并计算:
5x-
2
3
y
1
2
(-
1
4
x-1y
1
2
)(-
5
6
x
1
3
y-
1
6
)
答案
(1)2log32-log3
32
9
+log38-25log53
=log34-log3
32
9
+log38-52log53
=log3(4×
9
32
×8)-5log59
=log39-9=2-9=-7.
(2)∵x=27,y=64,
5x-
2
3
y
1
2
(-
1
4
x-1y
1
2
)(-
5
6
x
1
3
y-
1
6
)

=
5x-
2
3
y
1
2
(-
1
4
)×(-
5
6
x-1+
1
3
×y
1
2
-
1
6

=
5x-
2
3
y
1
2
5
24
×x-
2
3
×y
1
3

=24y 
1
6

=24×(26 
1
6

=48.
举一反三
(Ⅰ)计算(lg2)2+lg2•lg50+lg25;
(Ⅱ)已知a=
1
9
,求
3a
7
2


a-3

÷


3a-8
3a15


题型:解答题难度:一般| 查看答案
现定义:e=cosθ+isinθ,其中i为虚数单位,e为自然对数的底,θ∈R,且实数指数幂的运算性质对e都适用.如果a=
C05
cos5θ-
C25
cos3θsin2θ+
C45
cosθsin4θ
b=
C15
cos4θsinθ-
C35
cos2θsin3θ+
C55
sin5θ
,那么复数a+bi等于(  )
A.cos5θ+isin5θB.cos5θ-isin5θ
C.sin5θ+icos5θD.sin5θ-icos5θ
题型:单选题难度:简单| 查看答案
函数y=(x-1)2(x≤1)的反函数是(  )
A.y=1+


x
(x≥0)
B.y=1-


x
(x≥0)
C.y=1+


x
(x≤1)
D.y=1-


x
(x≤1)
题型:单选题难度:一般| 查看答案
计算:0.125-
1
3
+(2


2
-3)-1-[(-3)2]
1
2
+(π-


2
)0
题型:解答题难度:一般| 查看答案
计算:x10÷x5=______.
题型:填空题难度:一般| 查看答案
最新试题
热门考点

超级试练试题库

© 2017-2019 超级试练试题库,All Rights Reserved.