Let P be any point on the curve  9x2+16y2−144=0, but not on the axes. Let M,N be the feet of the perpendiculars drawn from P on minor and major axes respectively . Let the tangent at P cuts minor and major axes at R,T respectively. Let the normal at P cuts major axis at G and CF be the perpendicular from centre C to the normal at P. Then, which of the following is/are true?