Math Is Fun Forum

Hezekiah

Guest

surds

Evaluate this surd (1+√2÷√5+√3)+(1-√2÷√5-√3)

thickhead

Member

Registered: 2016-04-16

Posts: 1,086

Re: surds

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{1}Vasudhaiva Kutumakam.{The whole Universe is a family.}
(2)Yatra naaryasthu poojyanthe Ramanthe tatra Devataha
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Gophne

Member

Registered: 2016-10-16

Posts: 26

Re: surds

Let sqrt of 2 = a & sqrt of 3 = b and sqrt of 5 =c, the equation becomes
>> [(1+a)/(c+b)]+[(1-a)/(c-b)]
>> {[(1+a)(c-b)]+[(1-a)(c+b)]}/(c+b)(c-b)       ....LCD
>> [(c-b+ac-ab)+(c+b-ac-ab)]/(c^2-b^2)         ....simplification
>> 2(c-ab)/(c^2-b^2)                                      ....final simplification

From there you can substitute the values for a,b & c.

Please forgive my notation (answers always to be checked/confirmed!)

Rgds

Last edited by Gophne (2016-10-18 08:14:35)

ElainaVW

Member

Registered: 2013-04-29

Posts: 580

Re: surds

Hello:

Since everyone else just gives the answer. I'll try it.

[hidden text by admin.]

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: surds

Hi;

I have hidden your answer and Gophne has some interesting work there.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Gophne

Member

Registered: 2016-10-16

Posts: 26

Re: surds

Substituting back in would give

2[√5-√(2x3)]/2 = √5 - √6

(Please check all answers for accuracy before accepting )

Last edited by Gophne (2016-10-18 06:51:49)

thickhead

Member

Registered: 2016-04-16

Posts: 1,086

Re: surds

I mistook  ÷ for +. But what is the priority of ÷ over + and - ?

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{1}Vasudhaiva Kutumakam.{The whole Universe is a family.}
(2)Yatra naaryasthu poojyanthe Ramanthe tatra Devataha
{Gods rejoice at those places where ladies are respected.}

Monox D. I-Fly

Member

From: Indonesia

Registered: 2015-12-02

Posts: 2,000

Re: surds

It has been answered here.

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Actually I never watch Star Wars and not interested in it anyway, but I choose a Yoda card as my avatar in honor of our great friend bobbym who has passed away.
May his adventurous soul rest in peace at heaven.

thickhead

Member

Registered: 2016-04-16

Posts: 1,086

Re: surds

Does any body know exact rules regarding  order of operations involving

and "/"?

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{1}Vasudhaiva Kutumakam.{The whole Universe is a family.}
(2)Yatra naaryasthu poojyanthe Ramanthe tatra Devataha
{Gods rejoice at those places where ladies are respected.}