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1. Comparing coefficients C1! Bleugh!
OCR Jan 11 Question 2!

Find constants P and Q

(x-p)(2x^2 + 9x +10) = (x^2-4)(2x + q)
I expanded both sides and got
2x^3 + 9x^2 + 10x - 2px^2 - 9px -10p = 2x^3 + qx^2 - 8x - 4q

Now, when i look at that.. I honestly do not know what to do next :/
I can compare coefficients with simple equations, but this one is bleugh :/

Can someone guide me?
2. Re: Comparing coefficients C1! Bleugh!
OCR Jan 11 Question 2!

Find constants P and Q

(x-p)(2x^2 + 9x +10) = (x^2-4)(2x + q)
I expanded both sides and got
2x^3 + 9x^2 + 10x - 2px^2 - 9px -10p = 2x^3 + qx^2 - 8x - 4q

Now, when i look at that.. I honestly do not know what to do next :/
I can compare coefficients with simple equations, but this one is bleugh :/

Can someone guide me?

At the moment, it doesn't look too helpful to have a mixture of numbers, p's and q's, so put all the x's with a integer coefficient on one side and the p's + q's onto another, then compare.
3. Re: Comparing coefficients C1! Bleugh!
OCR Jan 11 Question 2!

Find constants P and Q

(x-p)(2x^2 + 9x +10) = (x^2-4)(2x + q)
I expanded both sides and got
2x^3 + 9x^2 + 10x - 2px^2 - 9px -10p = 2x^3 + qx^2 - 8x - 4q

Now, when i look at that.. I honestly do not know what to do next :/
I can compare coefficients with simple equations, but this one is bleugh :/

Can someone guide me?

Now compare the coefficients,

Solve the equations to find the values of 'p' and 'q'.
4. Re: Comparing coefficients C1! Bleugh!
Numbers on one side, variables on the other, then you can work them out easily.

9x^2 = 2px^2 + qx^2
18x = 9px
10p - 4q = 0x
Last edited by Brit_Miller; 12-05-2012 at 00:08.
5. Re: Comparing coefficients C1! Bleugh!
You need to gather your coefficients together. By this I mean simplify the left and right hand sides WITHOUT bringing anything on one side to the other.

Next, look at the coefficients for x^3, x^2, x and the constant term and create 4 equations of the form:

Left Hand side Right
x^3: ??? = ???
x^2: ??? = ???
x: ??? = ???
constant: ??? = ???

Fill in the blanks and solve each equation and you should get your p and q values.
6. Re: Comparing coefficients C1! Bleugh!
(Original post by raheem94)

Now compare the coefficients,

Solve the equations to find the values of 'p' and 'q'.
Hey, do you self teach yourself?
7. Re: Comparing coefficients C1! Bleugh!
Hey, do you self teach yourself?
Yes
8. Re: Comparing coefficients C1! Bleugh!
(Original post by WarriorInAWig)
You need to gather your coefficients together. By this I mean simplify the left and right hand sides WITHOUT bringing anything on one side to the other.

Next, look at the coefficients for x^3, x^2, x and the constant term and create 4 equations of the form:

Left Hand side Right
x^3: ??? = ???
x^2: ??? = ???
x: ??? = ???
constant: ??? = ???

Fill in the blanks and solve each equation and you should get your p and q values.
Thanks for the tips!
9. Re: Comparing coefficients C1! Bleugh!
May i ask.. How? what resources do you use
10. Re: Comparing coefficients C1! Bleugh!
(Original post by Brit_Miller)
Numbers on one side, variables on the other, then you can work them out easily.

9x^2 = 2px^2 + qx^2
18x = 9px
10p - 4q = 0x
Thanks for the tips!
11. Re: Comparing coefficients C1! Bleugh!
(Original post by Blazy)

At the moment, it doesn't look too helpful to have a mixture of numbers, p's and q's, so put all the x's with a integer coefficient on one side and the p's + q's onto another, then compare.
Thanks!!
12. Re: Comparing coefficients C1! Bleugh!
May i ask.. How? what resources do you use
I just use the edexcel modular text books to learn maths.
13. Re: Comparing coefficients C1! Bleugh!
(Original post by raheem94)
I just use the edexcel modular text books to learn maths.
Hmm, i'm on OCR. So you use the textbooks? Dayum, they're so black and white and dull :/ lol

I think i should start using them!

I usually learn everything on mymaths then just papers

Then again, i do end up with Cs :P
14. Re: Comparing coefficients C1! Bleugh!
Hmm, i'm on OCR. So you use the textbooks? Dayum, they're so black and white and dull :/ lol

I think i should start using them!

I usually learn everything on mymaths then just papers

Then again, i do end up with Cs :P
Edexcel ones aren't black and white, if you want to have a look at them, then you can download them, do you need the link?
15. Re: Comparing coefficients C1! Bleugh!
(Original post by raheem94)
Edexcel ones aren't black and white, if you want to have a look at them, then you can download them, do you need the link?
It's okay lol

I can't change boards :P School won't allow it
16. Re: Comparing coefficients C1! Bleugh!
It's okay lol

I can't change boards :P School won't allow it
But you can use the books for explanation.
17. Re: Comparing coefficients C1! Bleugh!
(Original post by raheem94)
But you can use the books for explanation.
oo, okay then

18. Re: Comparing coefficients C1! Bleugh!
19. Re: Comparing coefficients C1! Bleugh!
20. Re: Comparing coefficients C1! Bleugh!
Amazing!

Yo should set up a youtube channel and post videos about maths!
There are many better mathematicians to do this.

Remember the solution bank of these books only works in internet explorer and mozilla firefox.

Running it on firefox may require some changing in firefox setting.

It runs in internet explorer, but if you are using internet explorer 9 then you will need to watch my video to learn how to run it.