Mr M&#x27;s OCR (not OCR MEI) Core 1 answers May 2012

Original post by jameslad

Mr M

Do you mark papers as a job or are you just a teacher?

or can you be both lol?

both, I set papers too but not in the uk

Reply 182

frhe graph in question 5i), isnt it in the 1st and fourth quadrants because root 1 etc can be + or - 1... etc...

Reply 183

Original post by KoalaKim

frhe graph in question 5i), isnt it in the 1st and fourth quadrants because root 1 etc can be + or - 1... etc...

\sqrt{1}=1

\sqrt{1} \neq \pm 1

Reply 184

FK_

Could you not argue that 'between' is actually exclusive? although i doubt they'll deduct marks either way.

Reply 185

jameslad

Original post by Mr M

both, I set papers too but not in the uk

Wicked!!

So like are you given the Marking scheme when they tell you to mark papers?

Reply 186

Original post by Mr M

\sqrt{1}=1

\sqrt{1} \neq \pm 1

why? because

-1 * -1 is 1
and 1*1 is 1

I'm confused!!!

(edited 11 years ago)

Reply 187

klapsar

Original post by Mr M

You could probably still get 4 or 5 marks here

That makes me breathe a sigh of relief... 100% certain I actually got the correct answer for the question I thought I was answering. :zomg:

Reply 188

Original post by FK_

Could you not argue that 'between' is actually exclusive? although i doubt they'll deduct marks either way.

Possibly, I think it will ok either way too

Reply 189

Original post by jameslad

Wicked!!

So like are you given the Marking scheme when they tell you to mark papers?

Yes but it isn't published to markers for a few days - I should point out I won't be marking this paper or I wouldn't be answering questions about it

Reply 190

Original post by KoalaKim

why? because

-1 * -1 is 1
and 1*1 is 1

By definition. We say this is positive (even though numbers have two square roots). You might find this hard to believe but it avoids confusion!

If we want the other root we say

-\sqrt{1}

Reply 191

For this reason the graph of

y=\sqrt{x}

is different from the graph of

y^2=x

which is the complete parabola.

http://www.wolframalpha.com/input/?i=graph+real++y%3Dsqrt+x

http://www.wolframalpha.com/input/?i=graph+real++y%5E2%3Dx

Reply 192

Original post by Mr M

By definition. We say this is positive (even though numbers have two square roots). You might find this hard to believe but it avoids confusion!

If we want the other root we say

-\sqrt{1}

so does this mean that i won't get any marks?? because i drew it in 2 quadrants

Reply 193

Original post by KoalaKim

so does this mean that i won't get any marks?? because i drew it in 2 quadrants

1 out of 2 if it looked like the second graph in my previous post

Reply 194