AS questions - i'm stuck plz help!!!!! Watch

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clairezay
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#1
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Please could you tell me how I would simplify this:

sr=square root

sr3 (3 sr3 - sr 12)

thanks, that's the first question but there's a lot and i know we did it for gcse but i really forget, so if you could give me some help on that and explain how to do it so I can understand the rest and be alright with it in class, it'd be a great help!

thanks everyone
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dvs
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rt(12) = rt(4*3) = 2rt(3)

3rt(3) - 2rt(3) = rt(3)

You should know that square root of a = a^1/2, the cubic root of a = a^1/3, the fourth root of a = a^1/3, etc.

So, the 3rd root of [rt(3)] = (3^1/2)^1/3

Using the rules of indices:
(a^b)^c = a^(b*c)

So: (3^1/2)^1/3 = 3^(1/2*1/3) = 3^(1/6), or the sixth root of 3.

Hope that helps, and I hope I understood your question correctly.
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SsEe
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Wow. Your GCSE results are almost identical to mine. And I come from the hole they call Wirral too. Hehe.
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Euler
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(Original post by SsEe)
Wow. Your GCSE results are almost identical to mine. And I come from the hole they call Wirral too. Hehe.
How do u know this???? :rolleyes:
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llduncanll
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Isn't the question √3(3√3 - √12) ?

In which case the solution is:

= √3(3√3 - √12)
= √3(3√3 - 2√3) <======== (as √12 = √(4 x 3) = √4√3 = 2√3)
= 3√3√3 - 2√3√3
= 3(√3)² - 2(√3)²
= 9 - 6
= 3
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dan2004
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(Original post by clairezay)
Please could you tell me how I would simplify this:

sr=square root

sr3 (3 sr3 - sr 12)

thanks, that's the first question but there's a lot and i know we did it for gcse but i really forget, so if you could give me some help on that and explain how to do it so I can understand the rest and be alright with it in class, it'd be a great help!

thanks everyone
I think that the previous poster or I have become confused. I go the answer 3, as follows:
sr3*sr3=3, for obvious reasons. sr(12)=sr(4*3)=2sr3
so you then have :
sr3(3sr3-2sr3), which simplifies to sr3(sr3) which as previously mentioned is just 3.
hope this clarifies it for you.
Dan
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dan2004
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lol i must have posted right after you! sorry. so at least the answer 3 is confirmed
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llduncanll
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(Original post by dan2004)
lol i must have posted right after you! sorry. so at least the answer 3 is confirmed
lol no problem, 2 heads are better than 1...
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