Sin 30°•sin45°-sin60°-sin90°

Question

Sin 30°•sin45°-sin60°-sin90°

Answer 1

Sin 30°•sin45°-sin60°-sin90°=
=½•✓2/2-✓3/2-1=✓2/4 -✓3/2-1=
=(✓2-2✓3-4)/4