The notation of the norm of polynomials

[td21]

Homework Statement

attached

Homework Equations

The Attempt at a Solution

what is x_i? is it the coefficient of x or simply add up 1-5?
i found the notation different from http://mathworld.wolfram.com/PolynomialNorm.html
so i am confused. Thx!

 

[Char. Limit]

Basically, that middle part is equivalent to saying:

$$\sqrt{(x_1-x_1^2)^2 + (x_2-x_2^2)^2 + (x_3-x_3^2)^2 + (x_4-x_4^2)^2 + (x_5-x_5^2)^2}$$

Is that what you were asking?

 

[td21]

Basically, that middle part is equivalent to saying:

$$\sqrt{(x_1-x_1^2)^2 + (x_2-x_2^2)^2 + (x_3-x_3^2)^2 + (x_4-x_4^2)^2 + (x_5-x_5^2)^2}$$

Is that what you were asking?

sorry, i know the notation. But i don't know what x_i means? coefficient of x?

 

[Char. Limit]

No, it actually means the ith dimension of x, I believe.