In this opportunity I explain about number, more clear we see under this :
A. Kinds Of Numbers
1. Original number is positive integer
Example :
1, 2, 3, 4, 5, 6, . . . . . . . . .
2. Integer is number consisted of by positive integer, zero and number negative
. . . . . . ,-4, -3, -2, -1, 0, 1, 2, 3, 4, . . . . . .
3. Counting number is original number and zerol.
0, 1, 2, 3, 4, 5, 6, . . . . . . .
4. Prime number was original number which can only be divided with 1 and itself number.
Example :
2, 3, 5, 7, 11, 13, 17, 19, 23, . . . . . . . .
5. Rational number is number which can expressed as division of two integer, that is :
a/b ? an and b = integer, b ≠ 0
So rational number is integer, number that expressed with fraction or denary and its mixture.
6. Number irrasional is number which cannot expressed as division of two integers, or cannot expressed as :
a/b ? an and b = integer, b ≠ 0
Example :
Π = 3,14159 ..
2; 3, and so on
7. Real number ( R) is rational number aliance and number irrasional, or number which its(the unsure-unsur consisted of rational number and number irrasional.
R = { x|x = rational or x= irrasional }
8. Imaginary number is numbers marked by letter I from : infinite negativity until positive of clinegradasi".
9. Complex number is real number aliance with imaginary number.
Complex number usually is written down :
( a, b ) or a + bi
a is first tribe from a + bi called as real part.
b is second tribe from a + bi called as part which imaginary.
i called as imaginary unity.
Applies :
i2 = - 1
a + bi = 0 a = 0 and b = 0
a + bi = c + in ? a = c and b = d
Example of problem :
1. Determines number of from 6 odd original number that is first ?.
2. Determines many odd original numbers that is first the numbers 81 ?.
Reply :
1. Six odd original numbers that is first is 1, 3, 5, 7, 9, 11.
Hence nitrogen = 6
Number of from 6 first odd original number = n2
= 62
= 36
2. Number of odd original number nitrogens = n2 , hence :
n2 = 81
↔ n = 9 or n = - 9 ( doesn't fulfill)
So, many odd original numbers is 9.
Process explains friend number, to explain this number matter I assisted by my friend :
" Name : Fery Septianto
" Class : MAT NR 07
" NIM : 07305144041
" Place : My House
" Time : 14.00 wib
After I explain to Fery next to nothing its explanation internal issue, even in doing the problem of Fery can do during brief, nevertheless, still many the negatives.
Between of constraint experienced by :
" Explanation is using language english to find difficulties.
" Less can differentiate kinds of numbers.
" When in explaining a few are joking, because we seldom apply language english.
