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# C3 Mathematics watch

1. Could someone help with example 12 on page 9. I am unsure, what they mean by "comparing the coefficients in x3" and "comparing the coefficients in x2"

Thanks!!
2. The coefficient of x^3 is just the constant by which x^3 is multiplied; likewise for x^2. Since x can vary, for both sides of this equation to be identical regardless of the value of x, we need the coefficients for the different powers of x to be the same on each side.
So what you are doing is comparing the left hand side to the right hand side, as you know they are identical. The coefficient of x^3 is clearly 1. If you multiply out the right hand side, you will find that the only x^3 term is Ax^3. Hence A = 1.
You also know that the coefficient of x^2 is 1. If you multiply out the right hand side, you can similarly find B.
3. (Original post by 13 1 20 8 42)
The coefficient of x^3 is just the constant by which x^3 is multiplied; likewise for x^2. Since x can vary, for both sides of this equation to be identical regardless of the value of x, we need the coefficients for the different powers of x to be the same on each side.
So what you are doing is comparing the left hand side to the right hand side, as you know they are identical. The coefficient of x^3 is clearly 1. If you multiply out the right hand side, you will find that the only x^3 term is Ax^3. Hence A = 1.
You also know that the coefficient of x^2 is 1. If you multiply out the right hand side, you can similarly find B.
Thank you so much!!
4. (Original post by JamesNeedHelp2)
Could someone help with example 12 on page 9. I am unsure, what they mean by "comparing the coefficients in x3" and "comparing the coefficients in x2"

Thanks!!
Hows C3 and C4 ?I also do Maths and how difficult was the AS maths exams in the summer ?
Hows C3 and C4 ?I also do Maths and how difficult was the AS maths exams in the summer ?
I guess its subjective, harder for some, easier for others. ^^
6. (Original post by JamesNeedHelp2)
^^
If 2 polynomials are identical then each element has the same coefficient

Means a=e and b=f etc

If you have a problem to look at ... Please post it
7. (Original post by TenOfThem)
If 2 polynomials are identical then each element has the same coefficient

Means a=e and b=f etc

If you have a problem to look at ... Please post it
Thank you so much. I will do, if i get stuck.

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