Math Is Fun Forum

mathxyz

Member

From: Brooklyn, NY

Registered: 2024-02-24

Posts: 1,053

Classifying Numbers in a Set

Let N = set N

N = { -3, (4/3), sqrt{2}, pi, 10, 0.12, 2.151515. . . (Where the block 15 repeats }

Classify that the list of numbers in set N are natural, integers, rational, irrational and real.

Let me see.

Natural: 10

Integers: -3, 10

Rational: -3, (4/3), 0.12, 10, 2.151515

Irrational: sqrt{2}, pi

Real: All the numbers listed in set N are real numbers.

You say?

Phrzby Phil

Member

From: Richmond, VA

Registered: 2022-03-29

Posts: 50

Re: Classifying Numbers in a Set

But 2.151515 is not in your set N.

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World Peace Thru Frisbee

mathxyz

Member

From: Brooklyn, NY

Registered: 2024-02-24

Posts: 1,053

Re: Classifying Numbers in a Set

But 2.151515 is not in your set N.

Yes, it is. Look again. The decimal number 2.151515 is in set N.

Bob

Administrator

Registered: 2010-06-20

Posts: 10,621

Re: Classifying Numbers in a Set

I think the question was to determine which set this number was in.

Now may be the moment to start learning some Latex.

http://www.mathisfunforum.com/viewtopic.php?id=4397

Actually both the terminating number and the recurring one are rationals.  All rationals fall into one of these two categories. You may ask me to prove this if you want. 

Bob

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Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

mathxyz

Member

From: Brooklyn, NY

Registered: 2024-02-24

Posts: 1,053

Re: Classifying Numbers in a Set

I think the question was to determine which set this number was in.

Now may be the moment to start learning some Latex.

http://www.mathisfunforum.com/viewtopic.php?id=4397

Actually both the terminating number and the recurring one are rationals.  All rationals fall into one of these two categories. You may ask me to prove this if you want. 

Bob

The question is simply saying to place each number listed in set N in the correct category: rational, irrational, real, etc.

You said all rationals fall into two categories. Can you show the prove?

Bob

Administrator

Registered: 2010-06-20

Posts: 10,621

Re: Classifying Numbers in a Set

We've had this already here: http://www.mathisfunforum.com/viewtopic.php?id=29902

Bob

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Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

mathxyz

Member

From: Brooklyn, NY

Registered: 2024-02-24

Posts: 1,053

Re: Classifying Numbers in a Set

We've had this already here: http://www.mathisfunforum.com/viewtopic.php?id=29902

Bob

Thanks. I forgot about that post?