GCSE Maths Surds question help please

Original post by londoncricket

Hi all,

I was going through a past paper in preparation for my Maths exams in May and I was wondering whether someone would be able to help me with a maths question that I found in an Edexcel Maths paper (Monday 6 June 2011, Linear 1380/3H).

I have attached screenshots of the actual question and the answer. Obviously, I can just read the answer, but I don't know how to arrive at that answer.

I know how to rationalise, and I am very comfortable with surds, familiar, etc., but I haven't been able to fathom this one.

Many thanks in advance!

I'm going to be incredibly embarrassed if I'm wrong..

Reply 2

interstitial

18

Original post by londoncricket

Hi all,

I was going through a past paper in preparation for my Maths exams in May and I was wondering whether someone would be able to help me with a maths question that I found in an Edexcel Maths paper (Monday 6 June 2011, Linear 1380/3H).

I have attached screenshots of the actual question and the answer. Obviously, I can just read the answer, but I don't know how to arrive at that answer.

I know how to rationalise, and I am very comfortable with surds, familiar, etc., but I haven't been able to fathom this one.

Many thanks in advance!

\dfrac{8- \sqrt{18}}{\sqrt 2} \underbrace{\times \dfrac{\sqrt{2}}{\sqrt{2}}}_{= 1} = ?

(edited 10 years ago)

Reply 3

Zen-Ali

8

Original post by majmuh24

\dfrac{8- \sqrt{18}}{\sqrt 2} \underbrace{\times \dfrac{\sqrt{2}}{\sqrt{2}}}_{= 1} = \ ?

I thought full solutions were discouraged. :tongue:

(edited 10 years ago)

Reply 4

interstitial

18

Original post by Zen-Ali

I thought full solutions were discouraged. :tongue:

I'm in maths mode today, I can't help it! :colone:

I'll delete the last bit though, can you change your quote as well :redface:

Reply 5

Zen-Ali

8

Original post by majmuh24

I'm in maths mode today, I can't help it! :colone:

I'll delete the last bit though, can you change your quote as well :redface:

[Indent]I was gonna drop some advice, but then you solo’d the thread. xD

Diggin’ tha underbrace. :sexface:

[/Indent]

Reply 6

Hype en Ecosse

20

Original post by ILovePancakes

I'm going to be incredibly embarrassed if I'm wrong..

Hey! Great solution, but I just wanted to let you know that we discourage giving people the full solution to an answer straight away. People don't tend to learn very much that way, even though they feel like they might "get it". It's better to try to "egg on" the OP to try to help them get to the right answer on their own. :biggrin:

Loads of information about this here!

Reply 7

Original post by Hype en Ecosse

Hey! Great solution, but I just wanted to let you know that we discourage giving people the full solution to an answer straight away. People don't tend to learn very much that way, even though they feel like they might "get it". It's better to try to "egg on" the OP to try to help them get to the right answer on their own. :biggrin:

Loads of information about this here!

Oh dear.. I didn't realise :colondollar:

Do you want me to take it down?

Reply 8

Hype en Ecosse

20

Original post by ILovePancakes

Oh dear.. I didn't realise :colondollar:

Do you want me to take it down?

No, no. It's there now and OP will have likely seen it already. Might as well leave it, just this once. :wink:

Reply 9

Original post by Hype en Ecosse

No, no. It's there now and OP will have likely seen it already. Might as well leave it, just this once. :wink:

Haha, OK, thanks :biggrin:

I'll remember for next time :smile:

Reply 10

londoncricket

OP

17

Original post by ILovePancakes

I'm going to be incredibly embarrassed if I'm wrong..

Thanks for that, I will work that through myself later!

Reply 11