在三角形ABC中,a^2+b^2=1999c^2,则,cotC/cotA+cotB的值为?
在三角形ABC中,a^2+b^2=1999c^2,则,cotC/cotA+cotB的值为?
cotA+cotB都在 分母上
cotA+cotB都在 分母上
数学人气：733 ℃时间：2019-11-03 19:34:12
优质解答
cotC/cotA+cotB=(cosC/sinC)/[(cosA/sinA)+(cosB/sinB)]=[(cosC·sinA·sinB)/sinC]/(sinA·cosB+cosA·sinB)=(cosC·sinA·sinB)/[sinC·sin(A+B)]=(cosC·sinA·sinB)/[sinC·sin(π-C)]=(cosC·sinA·sinB)/(sinC...
我来回答
类似推荐
猜你喜欢
- 1甲,乙,丙三个工程队修建一条高速公路,甲工程队修了全长的百分之三十.
- 2英语翻译
- 3已知函数f(x)=log a (x+1=,g(x)=log a (1-x) (a大于0且a不等于1）.1,求函数f(x)+g(x)的定义域；2,判断函数f(x)+g(x)的奇偶性,并说明理由.
- 4You should always speak English in class.And you should write down your mistakes in your notebooks.求翻译
- 5It goes without saying that what we do
- 6i just don't know what to say,but i ‘m really sorry.的最佳答句是A.that'OK B.fogort it
- 7德智体美劳总结500
- 8一个长方体玻璃缸，从里面量，长50厘米，宽40厘米，高20厘米，现将1升水倒入玻璃缸中，水深_厘米．
- 9Describe a place you have visited from the following aspects
- 10像夏洛蒂,霍金,鲁滨逊这样的楷模还有哪些?