X=3+tsin20,Y=1-tcos20
tsin20=x-3
-tcos20=y-1 所以
-tan20°=(x-3)/(y-1)
y=(x-3)/(-tan20°)+1
k=-1/tan20°
设倾斜角为θ
tanθ=-1/tan20°
tanθ*tan20°=-1 0°
X=3+tsin20,Y=1-tcos20
tsin20=x-3
-tcos20=y-1 所以
-tan20°=(x-3)/(y-1)
y=(x-3)/(-tan20°)+1
k=-1/tan20°
设倾斜角为θ
tanθ=-1/tan20°
tanθ*tan20°=-1 0°