tanx=5/12,tany=4/3.x属于0,90,y属于180,270,求sin(x+y)_数学解答

tanx=5/12,tany=4/3.x属于0,90,y属于180,270,求sin(x+y)

人气：482 ℃　时间：2020-07-27 10:26:44

解答

tan(x+y)={tanx+tany]/(1-tanxtany)=(5/12+4/3)/(1-5/12*4/3)=(7/4)/(4/9)=63/16
又180°