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)<span> </span>
X-2=34+44
x-2=78
x=78+2
x=80
ответ:80
Графики прямой пропорциональности прикрепил
3x-21+4=7x-1
3x-7x=-1+21-4
-4x=16
x=-4