x=-1-tsinπ6/7,y=2+tcosπ/7 得t=-(1+x)/sinπ6/7=(y-2)/cosπ/7
(1+x)cosπ6/7=(y-2) sinπ6/7
y=ctgπ6/7x+ctgπ6/7+2
可知K=tga=ctgπ6/7=ctg(6π/7-π) =ctg(-π/7)=tg(π/2+π+7)=tg(9π/14)
倾斜角a=9π/14(好长时间没做三角函数了,化简可能啰嗦了)
x=-1-tsinπ6/7,y=2+tcosπ/7 得t=-(1+x)/sinπ6/7=(y-2)/cosπ/7
(1+x)cosπ6/7=(y-2) sinπ6/7
y=ctgπ6/7x+ctgπ6/7+2
可知K=tga=ctgπ6/7=ctg(6π/7-π) =ctg(-π/7)=tg(π/2+π+7)=tg(9π/14)
倾斜角a=9π/14(好长时间没做三角函数了,化简可能啰嗦了)