x=a+rcost
y=b+rsint
b+rsint=k(a+rcost-x0)+y0
rsint-krcost=k(a-x0)+y0-b
设sint-kcost=(k(a-x0)+y0-b)/r=C1
-√(1+k^2)cos(t-h)=C1 sinh=1/√(1+k^2)
设cos(t-h)=-C1/√(1+k^2)=C2
t=arccosC2+h=arccos(-k(a-x0)+y0-b)/r√(1+k^2))+arcsin(1/√(1+k^2))
x=a+rcos(arccos(-k(a-x0)+y0-b)/r√(1+k^2))+arcsin(1/√(1+k^2)))
y=b+rsin(arccos(-k(a-x0)+y0-b)/r√(1+k^2))+arcsin(1/√(1+k^2)))
另外一组解类似
想法是好的可惜太复杂不好运用