**A**- is a rational number.

**B**- is an irrational number.

You must prove that the sum of

**A+B**or the difference

**A-B**is an irrational number.

- Vega
- Keeper of the Board
**Posts:**2249**Joined:**Tue Sep 19, 2006 2:59 pm**Status:**English Learner-
**Contact:**

It is a simple little test. All you need to solve it- logical thinking.

**A**- is a rational number.

**B**- is an irrational number.

You must prove that the sum of**A+B** or the difference **A-B** is an irrational number.

You must prove that the sum of

- Krisi
- Ethereal Member
**Posts:**3831**Joined:**Fri Jul 20, 2007 9:48 am**Status:**English Learner**Location:**house

Xkalibur wrote:It is a simple little test. All you need to solve it- logical thinking.A- is a rational number.B- is an irrational number.

You must prove that the sum ofA+Bor the differenceA-Bis an irrational number.

Difficult Xkalibur!

As I understood it, the sum of a whole number plus a non-terminating (not sure of term) decimal will be an irrational number.

- Vega
- Keeper of the Board
**Posts:**2249**Joined:**Tue Sep 19, 2006 2:59 pm**Status:**English Learner-
**Contact:**

krisi wrote:Difficult Xkalibur!

As I understood it, the sum of a whole number plus a non-terminating (not sure of term) decimal will be an irrational number.

Yep.

Should I tell how to prove that or wait for some replies? I will tell you tomorrow.

- Krisi
- Ethereal Member
**Posts:**3831**Joined:**Fri Jul 20, 2007 9:48 am**Status:**English Learner**Location:**house

Xkalibur wrote:krisi wrote:Difficult Xkalibur!

As I understood it, the sum of a whole number plus a non-terminating (not sure of term) decimal will be an irrational number.

Yep.

Should I tell how to prove that or wait for some replies? I will tell you tomorrow.

I can wait Xkalibur. Yes, better to wait for some more replies..

- denvinbo
- Rough Diamond Member
**Posts:**1843**Joined:**Sat Dec 08, 2007 1:46 pm**Status:**English Learner**Location:**Vietnam-
**Contact:**

A hard test................

- Vega
- Keeper of the Board
**Posts:**2249**Joined:**Tue Sep 19, 2006 2:59 pm**Status:**English Learner-
**Contact:**

denvinbo wrote:A hard test................

Are you a schoolboy? What grade?

- denvinbo
- Rough Diamond Member
**Posts:**1843**Joined:**Sat Dec 08, 2007 1:46 pm**Status:**English Learner**Location:**Vietnam-
**Contact:**

9th.........

- Krisi
- Ethereal Member
**Posts:**3831**Joined:**Fri Jul 20, 2007 9:48 am**Status:**English Learner**Location:**house

Xkalibur,

Do you want a numerical value to prove it?

Do you want a numerical value to prove it?

- Vega
- Keeper of the Board
**Posts:**2249**Joined:**Tue Sep 19, 2006 2:59 pm**Status:**English Learner-
**Contact:**

krisi wrote:Xkalibur,

Do you want a numerical value to prove it?

No, there's no need for it. I'll show you how to do that in a logical way.

A- is a rational number.

B- is an irrational number.

==============

A+B or A-B

A+B=C

(A-B is similar to the above.)

Simple, isn't it?

- Krisi
- Ethereal Member
**Posts:**3831**Joined:**Fri Jul 20, 2007 9:48 am**Status:**English Learner**Location:**house

Xkalibur wrote:krisi wrote:Xkalibur,

Do you want a numerical value to prove it?

No, there's no need for it. I'll show you how to do that in a logical way.Answer.

A- is a rational number.

B- is an irrational number.

==============

A+B or A-B1. Let'spresumethat sum A+B is a rational number:

A+B=CC-> rational2. If so, then B:B=C-A would have been also rational as the difference of two rational numbers, but isn't so because it contradicts to the statement (B- an irrational number). Thus, our presumption wasfalseand therefore sum A+B is an irrational number.

(A-B is similar to the above.)

Simple, isn't it?

Yes, yes. Got it!

Thanks.

Users browsing this forum: No registered users and 2 guests

Powered by phpBB® Forum Software © phpBB Limited