1-x123
2-y123
3-B123
4-a 123
√ 126 * √ 14 = √ ( 126 * 14 ) = √ ( 7 * 9 * 2 * 2 * 7 ) = 7 * 3 * 2 = 42
(sinx - cosx)^2 + sin2x = 1
(sin^2x - 2sinxcosx + cos^2x) + sin2x =
Используем основное тригонометрическое тождество
= (sin^2x + cos^2x) - 2sinxcosx + sin2x =
= 1 - sin2x + sin2x ≡ 1
f(x) = ctg3x/3
f'(x) = -(3x)'/3sin^2 (3x) = -3/3sin^2 (3x) = -1/sin^2 (3x)
f'(x0) = f(-π/6) = -1/sin^2 (3(-π/6)) = -1/sin^2 (-π/2) = -1/1 = -1
Ответ : -1