But earlier steps suggest $ S = rac2(a^2 + b^2)a^2 - b^2 $. For $ |a| = |b| = 1 $, $ a^2 \overlinea^2 = 1 $, so $ a^2 = rac1\overlinea^2 $. This path is complex. Instead, let $ a = 1 $, $ b = -1 $: $ S = rac02 + rac20 $, invalid. Correct approach: Let $ a = e^i heta $, $ b = e^i\phi $, then - Portal da Acústica