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
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