Explicație pas cu pas:
[tex]sin 30° \times tg45°+cos30° \times ctg60° = \frac{1}{2} \times 1 + \frac{ \sqrt{3} }{2} \times \frac{ \sqrt{3} }{3} = \frac{1}{2} + \frac{1}{2} = 1[/tex]
[tex]sin60° \times cos60°+sin30° \times cos30°-sin45° \times cos45° = \frac{ \sqrt{3} }{2} \times \frac{1}{2} + \frac{1}{2} \times \frac{ \sqrt{3} }{2} - \frac{ \sqrt{2} }{2} \times \frac{ \sqrt{2} }{2} = \frac{ \sqrt{3} }{4} + \frac{ \sqrt{3} }{4} - \frac{1}{2} = \frac{ \sqrt{3} }{2} - \frac{1}{2} = \frac{ \sqrt{3} - 1}{2} [/tex]
