a little monkey was sitting on a tree. she was bored and she wanted to eat. she got down the tree and looked through the jungle to find a banana of a mango. but there was no fruits and even no tasty leafs. she was upset. she wandered through the jungle and meet her friends - green crocodile and bright parrot. parrot was very hungry too because he also couldn't find anything to eat. they decided to walk together. in a minute they noticed a huge yelow banana lying on the floor. monkey clutched it and at once many hunters with guns run to the glade.
friends started to run away. they ran through the bush and high grass and they saved their lives from the crafty hunters
Пошаговое объяснение:
1) i ^ 13 = (i^2)^6 * i = (-1)^6 * i = i
i^100 = (i^2)^50 = (-1)^50 = 1
i^1993 = (i^100)^19 * i^93 = 1 * (i^2)^46 * i = i
2) (1 + i)^10
Воспользуемся формулой Муавра
z^n = r^n(cos φn + i*sin φn)
r - модуль, φ - аргумент комплексного числа
В нашем случае r = √2, φ = 
/4
(1 + i)^10 = (√2)^10 * (cos 10/4 + i*sin 10/4) = 32*(cos 5/2 + i*sin 5/2)=
= 32*(0+i*1) = 32i
Другой вариант решения:
(1 + i)^10 = ( (1 + i)^2 )^5 = (1 - 2i + i^2)^5 = (1 + 2i - 1)^5 = (2i)^5 = 32i * i^4 = 32i
3) a = -1/2 + √3/2 * i
z^n = r^n(cos φn + i*sin φn)
Посчитаем модуль комплексного числа a:
r =√( (-1/2)^2 + (√3/2)^2) = 1
Аргумент φ = 2/3
a^4 = 1^4 * (cos 8/3 + i*sin 8/3) = -1/2 + i*√3/2 = a
a^11 = 1^11 * (cos 22/3 + i*sin 22/3) = -1/2 - i*√3/2
a^1992 = (a^4)^498 = a^498 =
= 1^498 * (cos 498*2/3 + i*sin 498*2/3) = cos 332 + i*sin 332 =
= 1
4) ( (1 + i)/(1 - i) )^1998 = ( (1 + i)^2 / 1^2 - i^2 )^1998 = ((1 + i)^2 / 2)^1998 =
= ((1^2 + 2i + i^2)/2)^1998 = ((1 +2i - 1)/2)^1998 = i^1998 = (i^2)^999 =
= (-1)^999 = -1
