tanx+tany=25,cotx+coty=30.tan(x+y)=?

分类: 作业答案 • 2022-01-09 18:01:45

问题描述：

tanx+tany=25,cotx+coty=30.tan(x+y)=?
RT

答

cotx+coty
=1/tanx+1/tany
=(tanx+tany)/(tnaxtany)
即30=25/(tanxtany),所以tanxtnay=5/6
tan(x+y)
=(tanx+tany)/(1-tanxtany)
=25/(1-5/6)
=150