X^3 - 7x^2 + 16x - 12 = 0
Сгруппируем
x^3 - 3x^2 - 4x^2 + 12x + 4x - 12 = 0
x^2 (x - 3) - 4x (x - 3) + 4(x - 3) = 0
(x - 3) (x^2 - 4x + 4) = 0
(x - 3) (x - 2)^2 = 0
x - 3 = 0
x = 3
(x - 2)^2 = 0
x - 2 = 0
x = 2
Ответ
2 ; 3
Решение
sinx = 1/23 <span>пи/2≤x≤пи
</span>ctgx = cosx/sinx
cosx = - √(1 - sin²x) = - √(1- (1/23)²) = - √(1 - 1/529) = - √(529 - 1)/529 =
= - √(528/529) = - (4√33) /23
ctgx = - [<span>(4√33) /23] : (1/23) = - 4</span>√33