3 * ( 2 + X ) > 4 - X
6 + 3X > 4 - X
3X + X > 4 - 6
4X > - 2
X > - 0,5
X ∈ ( - 0,5 ; + бесконечность )
cost = 3/4
cos(t/2) = ((1 + cost)/2)^(1/2) = ((1 + 3/4)/2)^(1/2) = (7/8)^(1/2) = (7^(1/2))/(2*(2^(1/2)))
sin(t/2) = (1 - cos^2(t/2))^(1/2) = (1 - 7/8)^(1/2) = 1/(8^(1/2)) = 1/(2*(2^(1/2)))
tg(t/2) = sin(t/2)/cos(t/2) = (1/(2*(2^(1/2))))/((7^(1/2))/(2*(2^(1/2)))) = 1/(7^(1/2))
ctg(t/2) = 1/tg(t/2) = 7^(1/2)
Сторона, лежащая напротив угла в 30° равна 1/2 гипотенузы. В=30° значит сторона В равна 1
тогда по теореме Пифагора сторона А равна: √4-1 = √3
(АВ+СВ)*АС=(2+√3)*1=2+√3