Math Is Fun Forum

Agnishom

Real Member

From: Riemann Sphere

Registered: 2011-01-29

Posts: 24,974

Website

Do this wihout the center of mass concept

Given: BD = DC; AE = ED

Prove: BE = 3 EX

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'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

Bob

Administrator

Registered: 2010-06-20

Posts: 10,145

Re: Do this wihout the center of mass concept

hi Agnishom,

You could use vectors:

Take A as the origin and AB = p as one vector and AD = q as another.

Express BD, DC, AE  and AC in terms of p and q.

Write a vector equation for the line BE and hence an expression with lambda for BX.  Hence AX.

Similarly a vector equation for AC and an expression for AX with a 'mu'.

Equate the expressions and solve for lambda and mu.  Show vector BE = 3EX.

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

thickhead

Member

Registered: 2016-04-16

Posts: 1,086

Re: Do this wihout the center of mass concept

Use concept: triangles with same height have area proportional to base.

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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.}

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Do this wihout the center of mass concept

Hi Mr, Chattopadhyay;

I rotated your image and I did not need eigenvalues to do it.

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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.

thickhead

Member

Registered: 2016-04-16

Posts: 1,086

Re: Do this wihout the center of mass concept

Last edited by thickhead (2016-06-02 19:39:53)

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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.}

Agnishom

Real Member

From: Riemann Sphere

Registered: 2011-01-29

Posts: 24,974

Website

Re: Do this wihout the center of mass concept

Thanks guys

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'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.