(1) Let m and n be perpendicular lines through the origin O and let σm and σn
denote the reflections about the lines m and n. Let σO denote the central
reflection in O. Show directly, using the formulae for σm and σn, that
σnσm = σO.
(1) Let m and n be perpendicular lines through the origin O and let σm and σn
denote the reflections about the lines m and n. Let σO denote the central
reflection in O. Show directly, using the formulae for σm and σn, that
σnσm = σO.