Consider three points P(–sin(β –α),–cosβ ), Q(cos(β –α), sinβ ) and R(cos(β –α+θ ), sin(β – θ )), where 0<α, β , θ < 4/π . Then
(a) P lies on the line segment RQ.
(b) Q lies on the line segment PR.
(c) R lies on the line segment QP.
(d) P, Q, R are non-collinear.