4x² + 1 = 0 a = 4 | b = 0 | c = 1
D = b² - 4ac = 0 - 4 * 4 * 1 = 0 - 16 = -16 < 0, корней нет
2m² - 3m = 8 -3m
2m² - 3m - 8 + 3m = 0
2m² - 8 = 0 a = 2 | b = 0 | c = -8
D = b² - 4ac = 0 - 4 * 2 * (-8) = -64 < 0, нет корней
3x² - 4x = 0 a = 3 | b = -4 | c = 0
D = b² - 4ac = 16 - 4 * 3 * 0 = 16 > 0, 2 корня
x₁ = -b + √D/2a = 4 + 4/6 = 8/6 = 4/3
x₂ = -b - √D/2a = 4 - 4/6 = 0/6 = 0
4x² - 9 = 0 a = 4 | b = 0 | c = -9
D = b² - 4ac = 0 - 4 * 4 * (-9) = 144 > 0, 2 корня
x₁ = -b + √D/2a = 0 + 12/8 = 12/8 = 3/2 = 1,5
x₂ = -b - √D/2a = 0 - 12/8 = -12/8 = -3/2 = -1,5
отметь как лучший!
x1 = -re(acos(-3)) + 2*pi - i*im(acos(-3))
x2 = 2*pi - i*im(acos(4))
x3 = re(acos(-3)) + i*im(acos(-3))
x4 = re(acos(4)) + i*im(acos(4))
Объяснение:
x1 = -re(acos(-3)) + 2*pi - i*im(acos(-3))
x2 = 2*pi - i*im(acos(4))
x3 = re(acos(-3)) + i*im(acos(-3))
x4 = re(acos(4)) + i*im(acos(4))
x1 = 3.14159265358979 + 1.76274717403909*i
x2 = 6.28318530717959 - 2.06343706889556*i
x3 = 3.14159265358979 - 1.76274717403909*i
x4 = 2.06343706889556*i
сумма
-re(acos(-3)) + 2*pi - i*im(acos(-3)) + 2*pi - i*im(acos(4)) + i*im(acos(-3)) + re(acos(-3)) + i*im(acos(4)) + re(acos(4))
=
4*pi + re(acos(4))
произведение
(((-re(acos(-3)) + 2*pi - i*im(acos(-3)))*(2*pi - i*im(acos(4*(i*im(acos(-3)) + re(acos(-3*(i*im(acos(4)) + re(acos(4)))
=
-(2*pi - i*im(acos(4)))*(i*im(acos(-3)) + re(acos(-3)))*(i*im(acos(4)) + re(acos(4)))*(-2*pi + i*im(acos(-3)) + re(acos(-3)))
x -скорость лодки
(х-3) - скорость против течения
(х+3) - скорость по течению
1 час 12 минут=1,2 часа
8/(х+3)+6/(х-3)=1,2
8x-24+6x+18
= 1,2
x^2-9
14х-6=1,2х^2-10,8
1,2x^2-14x-4,8=0
D/4=(14/2)^2+5,76
D/4=54,76
x1,2=(7+-7,4)/1,2
x1=-1.3 - не соответствует условию, т.к. скорость не может быть отрицательной
х2=12
ответ :12