Math Is Fun Forum

rp_

Member

Registered: 2006-02-10

Posts: 7

need help to solve the equation

can someone help me to solve this. If you could show me the steps you took it would be greatly appreciated.

(3√(16 - x²)/4) - 3 = (-3x/4√(16 - x²))(x - 2)

thanks in advance

irspow

Member

Registered: 2005-11-24

Posts: 1,055

Re: need help to solve the equation

After a good deal of expansion and then simplification I got;

  -x^6 + 4x^5 + 12x^4 -64x^3 + 100x^2 - 576 = 0

  Getting to the point above is nothing more that a matter of patience(?).  Solving the above however is no easy task.  The best that I have seen here with this sort of problem is krassi holmz, perhaps he will give you the answer you seek.  I could plug this into my TI-89, but I don't think that that is what you are looking for, so I leave it to more talented people who hang around here.

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I am at an age where I have forgotten more than I remember, but I still pretend to know it all.

krassi_holmz

Real Member

Registered: 2005-12-02

Posts: 1,905

Re: need help to solve the equation

A hunt-you can find the exactly roots.

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IPBLE:  Increasing Performance By Lowering Expectations.

krassi_holmz

Real Member

Registered: 2005-12-02

Posts: 1,905

Re: need help to solve the equation

Last edited by krassi_holmz (2006-02-11 03:53:40)

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IPBLE:  Increasing Performance By Lowering Expectations.

krassi_holmz

Real Member

Registered: 2005-12-02

Posts: 1,905

Re: need help to solve the equation

So:

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IPBLE:  Increasing Performance By Lowering Expectations.

irspow

Member

Registered: 2005-11-24

Posts: 1,055

Re: need help to solve the equation

You sir, are a factoring GOD!  I could have looked at that for the rest of my life and not saw those factors.  I bow before you.

Just curious.  How did you become so proficient at seeing factors?  Is it something that can be taught or is it a personal talent?

Last edited by irspow (2006-02-11 04:03:54)

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I am at an age where I have forgotten more than I remember, but I still pretend to know it all.

krassi_holmz

Real Member

Registered: 2005-12-02

Posts: 1,905

Re: need help to solve the equation

Good task.

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IPBLE:  Increasing Performance By Lowering Expectations.

krassi_holmz

Real Member

Registered: 2005-12-02

Posts: 1,905

Re: need help to solve the equation

Here's the talent:
You write something like this in Mathematica:
Factor[-x^6 + 4x^5 + 12x^4 -64x^3 + 100x^2 - 576]
and after less than a second it's factorized.

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IPBLE:  Increasing Performance By Lowering Expectations.

irspow

Member

Registered: 2005-11-24

Posts: 1,055

Re: need help to solve the equation

Shucks!  I thought that you were "Rain Man" or something.

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I am at an age where I have forgotten more than I remember, but I still pretend to know it all.

krassi_holmz

Real Member

Registered: 2005-12-02

Posts: 1,905

Re: need help to solve the equation

I can be "Rain Man" in spite of using Mahematica.

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IPBLE:  Increasing Performance By Lowering Expectations.

debra1234

Guest

Re: need help to solve the equation

help me solve this equation  2y square+ 14y=0

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: need help to solve the equation

2y² + 14y = 0
2y(y+7) = 0

∴ y = 0 or -7.

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Why did the vector cross the road?
It wanted to be normal.