Question

Oblicz:a) 2 sin45°- tg²60°
b)sin²60°+cos²60°
c)tg30°x ctg30°-cos²45°
przyjmujemy ze (sin α)²=sin²α, (cos α)²=cos² α, (tg α)²=tg² α
(α=alfa)

Answer 1

A) 2 sin45°- tg²60° = 2*(√2):2 - (√3)² = √2 -3


b)sin²60°+cos²60° = (√3:2)² + (½)² = ¾ +¼ = 1


c)tg30°x ctg30°-cos²45° = (√3):3 *√3 - (√2:2)² = ⅓ - (2/4) = ⅓ - ½ = 2/6 -3//6 = -1/6