Question

Oblicz: a) 2 sin (kwadrat) 45 + 7 tg 30 * cos 60 b) (ctg60 - tg60) kwadrat - (ctg60 + tg60) kwadrat

Answer 1

a)2·sin²45+7tg30·cos60=2·(√2/2)² +7·√3/3 ·½ =2·½·(7√3)/6 =1·(7√3)/3=2⅓√3

b)(ctg60-tg60)²-(ctg60+tg60)² =(√3/3-√3)²-(√3/3+√3)² =(3/9-2 -3)-(3/9+2+3)=

1/3 -5 -1/3 -5 =-10