Show that : = (sin A)\sin(90° - A) + (cos A)\cos(90° - A) = sec A cosec A

To prove: = sec A cosec A By formula, sin (90° - A) = cos A and cos (90° - A) = sin A. Substituting above values in L.H.S. : By formula, sin 2 A + cos 2 A = 1 Since, L.H.S. = R.H.S. Hence, proved that = sec A cosec A.