12х+1=12х+1
12х-12х=1-1
0х=0
(1-2sin²0,5х)*<span>cos0.5x </span> -0,5sin0.5x*2<span>cos0.5x </span>sin0.5x=
cos0.5x (1-2sin²0,5х-sin²0,5х)=
cos0.5x (1-3sin²0,5х)
Сначала определяем знак каждого множителя.
(-4-3i) + (1+3i) = (-4+1)+(-3i+3i) = -3+0=3
(-4i-3i) - (1+3i) = (-4-1) + (-3i -3i) = -5 -6i
(-4-3i)(1+3i) = -4 - 3i - 12i -9i² = -4 -15i +9 = 5 - 15i
![\frac{(-4-3i)(1-3i)}{(1+3i)(1-3i)}= \frac{-4-3i+12i+9i^2}{1^2-9i^2}= \frac{-4+9i-9}{1+9}= \frac{-13+9i}{10}=-1.3+0.9i](https://tex.z-dn.net/?f=%20%5Cfrac%7B%28-4-3i%29%281-3i%29%7D%7B%281%2B3i%29%281-3i%29%7D%3D%20%5Cfrac%7B-4-3i%2B12i%2B9i%5E2%7D%7B1%5E2-9i%5E2%7D%3D%20%5Cfrac%7B-4%2B9i-9%7D%7B1%2B9%7D%3D%20%5Cfrac%7B-13%2B9i%7D%7B10%7D%3D-1.3%2B0.9i%20%20%20%20)