Răspuns:
1. [tex]- \frac{\sqrt{2} }{2}[/tex]
2. [tex]\frac{\sqrt{6}-1 }{2}[/tex]
Explicație pas cu pas:
1.
[tex]sin30 = \frac{1}{2}[/tex]
[tex]cos45 = \frac{\sqrt{2} }{2}[/tex]
[tex]sin60 = \frac{\sqrt{3} }{2}[/tex]
[tex]tg30 = \frac{\sqrt{3} }{3}[/tex]
[tex]sin30 - cos45 - sin60 *tg30 = \frac{1}{2} - \frac{\sqrt{2} }{2} - \frac{\sqrt{3} }{2} *\frac{\sqrt{3} }{3}[/tex]
[tex]= \frac{1-\sqrt{2} }{2} - \frac{3}{6}[/tex]
[tex]= \frac{1-\sqrt{2} }{2} - \frac{1}{2}[/tex]
[tex]= \frac{1-\sqrt{2} -1}{2}[/tex]
[tex]= -\frac{\sqrt{2} }{2}[/tex]
2.
[tex]tg 60 = \sqrt{3}[/tex]
[tex]sin45 = \frac{\sqrt{2} }{2}[/tex]
[tex]ctg 45 = 1[/tex]
[tex]cos 60 = \frac{1}{2}[/tex]
[tex]tg60 * sin45 - ctg45 *cos60 = \sqrt{3} * \frac{\sqrt{2} }{2} - 1*\frac{1}{2}[/tex]
[tex]= \frac{\sqrt{6} }{2} - \frac{1}{2}[/tex]
[tex]= \frac{\sqrt{6} - 1}{2}[/tex]
