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  Discussion about math, puzzles, games and fun.   Useful symbols: √ ∞ ≠ ≤ ≥ ≈ ⇒ ∈ Δ θ ∴ ∑ ∫ π -

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Topic review (newest first)

MathsIsFun
2005-07-23 07:50:20

Another way to look at it is to think that a square root is also x^ (x raised to the half power)

For example √x = x is is the same as saying (x)^ = x^(2/2) = x^1 = x

So, 4√xy x 4√xy = x^(3/4) y^(1/4) x^(1/4) y^(2/4)

Combining terms: x^(4/4) y^(3/4)

Simplifying: x y^(3/4)  = x 4√y  (x times fourth root of y cubed)

mathsyperson
2005-07-23 04:06:04

√a x √b= √(a x b), so 4√xy x 4√xy = 4√(xy x xy)

Multiply the terms: 4√((x^4)y)
4√x^4=x, so taking x out of the 4th root gives x(4√y)

Your answer should have the 4th root of y instead of the square root.
So, yes, minor typo error.

samsoo
2005-07-23 03:48:50

One more thing, is this a typo error agian or correct answer?

http://usera.imagecave.com/samsoo/simp.JPG

samsoo
2005-07-23 03:43:11

Hi thx for the reply.

You're right, it does work if there's a plus sign between 3/2(x-1) and √(2x-7x-4). I checked the question and there's no plus sign, so I guess it could be a typo error.

I was given a typed up booklet just to familiarise and practise on, I hope there's no more other typos or I'll just get stressed up for doing wrong questions.

mathsyperson
2005-07-23 01:04:03

I tried working backwards by squaring the answer, and found that you actually want to find to square root of:

3/2(x-1)+√(2x-7x-4)

I wouldn't have any idea how to solve it if you hadn't already given us the answer though.
Squaring is easy, you can just follow a set of rules to get the answer every time.
Isn't it weird how the inverse can be so much more horrible?

samsoo
2005-07-22 23:44:01

Hi all.

I'm new here and need some help with this maths problem.

http://usera.imagecave.com/samsoo/sqrroot.JPG

Here's a pic of the question and the answer and I've tried doing a method but my head can't get round this.

Any help appreciated.

Thanks in advance.

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