For the curve x(t)=10−10cos(t),y(t)=11−11sin(t),0≤t≤2π, find all points where the tangent line is cither horizontal or vertical. (Give your answers as comma-separated lists of point coordinates in the form (6,4). Express numbers in exact form. Use symbolic notation and fractions where needed. Enter DNE if there are no such points.)
Points where tangent line is horizontal:___________