sinθ=m-3/m-5,cosθ=4-2m/m+5,?应为：sinθ=(m-3)/(m+5),cosθ=(4-2m)/(m+5),才对.因为(sinθ)^2+(cosθ)^2=1,所以[(m-3)/(m+5)]^2+[(4-2m)/(m+5)]^2=1,整理,得：4m^2-32m=0,所以m=0,或m=8.当m=0时,sinθ=3/5,cos...