4、两直线[img=165x51]1803bbf043d871c.png[/img]与[img=169x43]1803bbf04bb5081.png[/img]的夹角为（ ）
A: [img=78x48]1803bbf054c9a69.png[/img]
B: [img=78x48]1803bbf05da8677.png[/img]
C: [img=78x48]1803bbf065b5469.png[/img]
D: [img=78x48]1803bbf06db6d45.png[/img]
A: [img=78x48]1803bbf054c9a69.png[/img]
B: [img=78x48]1803bbf05da8677.png[/img]
C: [img=78x48]1803bbf065b5469.png[/img]
D: [img=78x48]1803bbf06db6d45.png[/img]
举一反三
- 4、两直线[img=165x51]1803bbf182c185e.png[/img]与[img=169x43]1803bbf18ab08b4.png[/img]的夹角为（ ） A: [img=78x48]1803bbf1935a8df.png[/img] B: [img=78x48]1803bbf19b54c02.png[/img] C: [img=78x48]1803bbf1a38c305.png[/img] D: [img=78x48]1803bbf1ab0f171.png[/img]
- 某均匀平面波由空气斜入射到位于Z<0区域的理想介质（[img=154x22]180332d7c43dab5.png[/img]）面，其入射角为30度，则相应的折射角为（ ）度。 A: [img=62x43]180332d7cd3aa0b.png[/img] B: [img=78x48]180332d7d6a4685.png[/img] C: [img=62x43]180332d7df8db16.png[/img] D: [img=78x48]180332d7e8c9976.png[/img]
- 某均匀平面波由空气斜入射到位于Z<0区域的理想介质（[img=154x22]180332d8a610ab7.png[/img]）面，其入射角为30度，则相应的折射角为（ ）度。 A: [img=62x43]180332d8adb3522.png[/img] B: [img=78x48]180332d8b5e58fa.png[/img] C: [img=62x43]180332d8bee1ce2.png[/img] D: [img=78x48]180332d8c78b358.png[/img]
- Which of the following propositions is false,set A = {x,x is an integer and[img=60x23]1803a1c6eebb7a3.png[/img]} ? ( ) A: [img=113x25]1803a1c6f77ce06.png[/img] B: [img=139x25]1803a1c7001fe79.png[/img] C: [img=51x22]1803a1c70863f61.png[/img] D: {x|x is an integer and |x| 4}[img=33x22]1803a1c711a7c63.png[/img]
- Which of the following propositions is false,set A = {x,x is an integer and [img=60x23]1803a1c503ffa04.png[/img]} ? ( ) A: [img=113x25]1803a1c50cc3162.png[/img] B: [img=139x25]1803a1c514e60ea.png[/img] C: [img=51x22]1803a1c51dd52ef.png[/img] D: {x|x is an integer and |x| <4} [img=33x22]1803a1c525cf1bd.png[/img]