replace r=cot theta sec theta in cartesian equation
If you mean convert from polar to rectangular coordinates, then
r = cotθ secθ
r = cosθ/sinθ * 1/cosθ
r = 1/sinθ
rsinθ = 1
y = 1
r = cotθ secθ
r = cosθ/sinθ * 1/cosθ
r = 1/sinθ
rsinθ = 1
y = 1