若0若0
若0tanx=1/7,tany=3/4则tan(x+y)=(tanx+tany)/(1-tanxtany)=(1/7+3/4)/[1-(1/7)*(3/4)]=1又0<x<π/2,0<y<π/2则0<x+y<π所以x+y=π/4如果不懂,请Hi我,祝学习愉快!
tan(x+y)=(tany+tanx)/(1-tanx*tany)tan(x+y)=1and 0so x+y=π/4