不查表求cos80°cos35°+cos10°cos55°的值．_爱下问搜题

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问题解答题

不查表求cos80°cos35°+cos10°cos55°的值．

答案

原式=sin10^°cos35^°+cos10^°sin35^°=sin（10^°+35^°）=sin45^°=

2

2

填空题

选择适当的词组填空。根据所提供的语景，从方框中选择正确的短语填空完成句子：

in memory of , in rags, turn up, by accident , cut down,
cheered up, dress up, settle down, go ahead; have a gift for

1. I expect the missing watch will _______ one day.
2. The pilot, whether _____or design, made the plane do a sharp turn.
3. The library was built ______ the scientist.
4. As they don't have enough gas, they have decided to ______gas supplies to other cities.
5. The good news _________ whoever heard it.
6. -I wonder if I could use your dictionary.  -Sure, _____.
7. He _________ making everybody around him happy.
8. On Halloween, children would _____ and go door to door asking for treats or playing tricks.

填空题

TD-SCDMA基本搭建起完成的产业链架构，但是产业链主要以（）为主，特别是（）和（）环节，更是很多都是（），综合实力较弱。