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1. So I have this question:

For b, I got p = 3-2√2 and 3+2√2. The mark scheme says the answer is:

p<3-2√2 or p>3+2√2

How do I know whether to put "or" or just write it like: 3+2√2 < p < 3-2√2 ?
2. (Original post by кяя)
So I have this question:

For b, I got p = 3-2√2 and 3+2√2. The mark scheme says the answer is:

p<3-2√2 or p>3+2√2

How do I know whether to put "or" or just write it like: 3+2√2 < p < 3-2√2 ?
You sketch the graph of . Always sketch the graph, it doesn't need to be elaborate, just a U if the number in front of p^2 is positive and an upside down u it's negative.

Label the roots (where it cuts the axis) as your values.

Then you know that you want the graph to be >0, that is, above the p-axis. That's precisely the region that >second root and <first root.

Had it asked you for p^2 - 6p + 12 < 0, then you would want the region where the graph is under the x-axis which is in between the two roots, so 3 - sqrt(blah) < p < blah
3. (Original post by Zacken)
so 3 - sqrt(blah) < p < blah
4. (Original post by Alexion)
I got lazy towards the end.
5. (Original post by кяя)

How do I know whether to put "or" or just write it like: 3+2√2 < p < 3-2√2 ?
Well the value on the left is greater than the value on the right, so that can't be correct.
6. Oh, I get it now. Thanks guys!! repped
7. (Original post by кяя)
Oh, I get it now. Thanks guys!! repped
No problem.

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