Question

Алгебра.Тригонометрия
А10,В1,В2

Answer 1

А10.    tg (2π - π/4) = tg π/4 = 1
В1   Cos² a = 1 - Sin² a = 1 - 91/100 = 9/100
    Cos a = 3/10
В2   4√2·Сosπ/4·Сos7π/3 = 4√2·√2/2·1/2= 2

Answer 2

а где B1 и B2?