1 . 给出下列四个命题:
(1)若
为假命题,则
均为假命题;
(2)命题“
”为真命题的一个充分不必要条件可以是
;
(3)已知函数
,则
;
(4)若函数
的定义域为
,则实数
的取值范围是
.
其中真命题的个数是
(1)若
![](https://img.xkw.com/dksih/QBM/2016/10/25/1573093733056512/1573093738708992/STEM/7aef61e5e52646d09c07e7786b71fc28.png)
![](https://img.xkw.com/dksih/QBM/2016/10/25/1573093733056512/1573093738708992/STEM/43ab18badfe1443898d418fe742babd5.png)
(2)命题“
![](https://img.xkw.com/dksih/QBM/2016/10/25/1573093733056512/1573093738708992/STEM/72b48a07ea5647eda7985b0e3a0872f9.png)
![](https://img.xkw.com/dksih/QBM/2016/10/25/1573093733056512/1573093738708992/STEM/ebb1c7812ab44ee3b6351d0b36004322.png)
(3)已知函数
![](https://img.xkw.com/dksih/QBM/2016/10/25/1573093733056512/1573093738708992/STEM/d0f043ca221d4f7593b7f8a20d258155.png)
![](https://img.xkw.com/dksih/QBM/2016/10/25/1573093733056512/1573093738708992/STEM/369d0f62946745d09ed376839d64adc4.png)
(4)若函数
![](https://img.xkw.com/dksih/QBM/2016/10/25/1573093733056512/1573093738708992/STEM/985c9af6f27c45e0acb6c6611379053a.png)
![](https://img.xkw.com/dksih/QBM/2016/10/25/1573093733056512/1573093738708992/STEM/be74c73ca843431d90d2585585cd6c76.png)
![](https://img.xkw.com/dksih/QBM/2016/10/25/1573093733056512/1573093738708992/STEM/c39f09eb37fa44cfac94ae27fa995575.png)
![](https://img.xkw.com/dksih/QBM/2016/10/25/1573093733056512/1573093738708992/STEM/40fbd1b2bdcf414b88fd094b92632257.png)
其中真命题的个数是
A.0 | B.1 | C.2 | D.3 |
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A.0 | B.1 | C.2 | D.3 |