1) cost = 12/13, 3π/2 < t < 2π , 4 четверть
sint = - √[1 - (12/13)²] = - √(25/169) = - 5/13
tgt = sint/cost
tgt = - 5/13 : 12/13 = - 5/12
ctgt = - 12/5
2) 2sint / (- sint) = - 2
3) 2sin²x + sinx - 1 = 0
D = 1 + 4*2*1 = 9
a) sinx = (-1 - 3)/4
sinx = - 1
x₁ = - π/2 + 2πk, k∈Z
b) sinx = ( - 1 + 3)/4
sinx = 1/2
x = (-1)^(n)*arcsin(1/2) + πn, n∈Z
x₂ = (-1)^(n)*(π/6) + πn, n∈Z
4) a) y = (3x - 4)⁶
y` = 6(3x - 4)⁵ *3 = 18*(3x - 4)⁵
b) y = √(4x - 5)
y` = (1/2)*(4x - 5)^(-1/2)* 4 = 2 /(√(4x - 5)
c) y = - 3/(x² - 4)
y = - 3*(x² - 4)^(-1)
y` = -3*(-1)(x² - 4)^(-2) * (2x) =(6x) / (√(x² - 4)