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another maths question - Printable Version

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another maths question - Elfy - 10-20-2011 04:08 AM

[Image: image.jpg]

It's a rearrange equation? Hidden quadratic?


RE: another maths question - Aya - 10-20-2011 04:43 AM

Yes it is. I'm working on it right now.


RE: another maths question - Elfy - 10-20-2011 04:57 AM

I'm thinking:

sqrt(t) = 4 + 12/sqrt(t

rearrange

t-4sqrt(t) - 12 = 0

(sqrt(t) - 6)(sqrt(t) + 2) = 0

6 or -2

t = 36


RE: another maths question - Prince Rilian - 10-21-2011 10:17 AM

Why did you eliminate 4? I can't see the image in the first post.


RE: another maths question - sergeant - 10-21-2011 11:39 AM

FUCKING fail no picture at the beginning


RE: another maths question - Elfy - 10-21-2011 02:15 PM

wut?

original is:

solve

sqrt(t) = 4 + 12/sqrt(t)


RE: another maths question - Prince Rilian - 10-21-2011 02:52 PM

So why did you eliminate 4? Something about principle roots?


RE: another maths question - Efs - 10-23-2011 06:28 AM

I'm alright at Math, but what's the question I don't understand...


RE: another maths question - sergeant - 10-23-2011 06:59 AM

sqrt(t) = 4 + 12/sqrt(t)

Multiply both sides by sqrt(t)

t = 4sqrt(t) + 12

Subtract 12 from both sides (you're isolating the root)

t - 12 = 4sqrt(t)

Square both sides

t^2 - 24t +144 = 16t

Subtract 16t from both sides

t^2 - 40t + 144 = 0

Now you have a quadratic equation. HIDDEN QUADRATIC

36, 4

If you input 4 you will realize it is the opposite of the root and it won't work. Square roots refer only the the positive number which when squared equals the original. Oh well.

36 = t