ПОМОГИТЕ РЕШИТЬ 2 ЗАДАНИЯ ! (ПОДРОБНОЕ РЕШЕНИЕ)

Y = 1 / [tgx];
1) x = 5pi/6;
y = 1 / [tg 5pi/6]= 1 / [- √3/3] = 1/ (√3/3) = 3/√3 = √3.
2) x = 3 pi/2;
y = 1 / [tg 3pi/2]= 1/ ∞ = 0.
3) x = - pi/6.
y = 1 / [tg(- pi/6)] = 1 / [- √3/3]=1/ √3/3 = 3 / √3 = √3.
4) y = - 2pi/3;
y = 1 / [tg(-2pi/3)] = 1 / [√3] = 1/ √3 = √3/3.
1.
y = ctg x; x = 5 pi/6.
y(5pi/6) = ctg(5pi/6) = ctg(- pi/6) = - ctg(pi/6) = - √3.
y = ctg (x/2) ;x = pi/2.
y( pi/2) = ctg(pi/4) = 1.