题目
题型:安徽模拟难度:来源:
1 |
x |
1 |
y |
a |
x+y |
A.1 | B.
| C.2 | D.4 |
答案
1 |
x |
1 |
y |
a |
x+y |
1 |
x |
1 |
y |
而(x+y)(
1 |
x |
1 |
y |
y |
x |
x |
y |
|
即(x+y)(
1 |
x |
1 |
y |
若(x+y)(
1 |
x |
1 |
y |
则a的最大值是4;
故选D.
核心考点
举一反三
a2 |
2 |
1 |
ab |
1 |
a2-ab |
A.
| B.2
| C.3 | D.4 |
a |
2 |
sinx |
-1 |
sinx |
b |
π |
2 |
(Ⅰ)若
a |
b |
(Ⅱ)若f(x)=
a |
b |
1 |
x |
1 |
y |
a |
x+y |
A.1 | B.
| C.2 | D.4 |
1 |
x |
1 |
y |
a |
x+y |
1 |
x |
1 |
y |
1 |
x |
1 |
y |
y |
x |
x |
y |
|
1 |
x |
1 |
y |
1 |
x |
1 |
y |
a2 |
2 |
1 |
ab |
1 |
a2-ab |
A.
| B.2
| C.3 | D.4 |
a |
2 |
sinx |
-1 |
sinx |
b |
π |
2 |
a |
b |
a |
b |