sin平方30°-tan平方45°+二分之三乘tan30°-sin60°乘cos45°
原式=﹙1/2﹚²﹣1²﹢﹙3/2﹚×﹙√3/3﹚﹣﹙√3/2﹚×﹙√2/2﹚
=1/4﹣1﹢√3/2﹣√6/4
=﹙-3﹢2√3﹣√6﹚/4