I need help with finding out what type of number something is. like if its a Rational number or an Integer or Irrational number. stuff like that! (Algebra 1)
ill help :)
first off we have the natural numbers, these are just the normal counting numbers: 1,2,3,4,5,6,......
then we have the integers, these are the natural numbers AND the negative whole numbers: ...,-5,-4,-3,-3,-1,0,1,2,3,4,5,..
then we have the rational numbers, these are numbers that we get when we divide integers by each other for example 1/2 , 3/5 , -2/3 are all rational numbers. remember all integers are rationals because we can write them like this: \[5= \frac{5}{1}\]
alrighty! I need to know about 6 different kinds of numbers! Natural Numbers, Whole Numbers, Integers, Rational Numbers, Irrational Numbers, and Real Numbers
ok :D so far i have done naturals, integers, and rationals. "whole numbers" can mean different things depending on what you're talking about, when i think of whole numbers i think of integers, and they're basically the same thing
Irrational Numbers are any numbers you cant write as a ratio of integers. for example the square root of 2 cannot be written as a fraction.
well my teacher said that almost all these things can equal one another.Like a natural number can be a whole number and a whole number can be an integer that can be a rational number which is a real number
ill draw a diagram that might help with that bit
think of this circle as the Real Numbers. probably all numbers you've seen are Real Numbers, there are other types of numbers that aren't real, but i wont talk about them (unless you want me to after this) |dw:1346195754210:dw|
lets split the circle to show the rationals and the irrationals: |dw:1346195831005:dw|
here is where the integers live: |dw:1346195921875:dw|
and the naturals: |dw:1346195972036:dw|
|dw:1346195939578:dw|
thats kinda like what she made for us
nice! yeah thats much better than my drawing
is there anything more you want me to explain about it?
|dw:1346196094979:dw|
That actually helps alot! So fractions are always an integer and irrationals are always a square root?
all integers are rational (fractions), rationals (fractions) aren't necessarily integers. eg 1/2 is NOT an integer, but 6 IS a rational
how is 6 rational?
because 6 can be written like this : \[\frac{6}{1}\]
irrationals dont have to be a square root, for example pi is irrational
okay but if it is a squareroot is it irrational?
only some (i know, this is probably a bit frustrating) square roots of numbers that AREN'T square are irrational eg \[\sqrt{2} \text{ is, but } \sqrt{4} \text{ isn't}\] because the square root of 4 is 2
also other roots can be irrational: \[\sqrt[3]{2}\]
okay thanksss
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