- Thread starter
- #1

- Thread starter Juliayaho
- Start date

- Thread starter
- #1

What is \(\displaystyle \displaystyle \mu \) representing?This is part 2 of a question... I already solved part 1 but I can't seem to be able to solve this one.

Interpret the measure √2 μ geometrically?

Any ideas... This is from real analysis class

Thanks in advance!

- Thread starter
- #3

The unique positive regular measure on B(R^2) such that for all f in C_c(R^2) λf= ∫_R^2 f dµ

- - - Updated - - -

The unique positive regular measure on B(R^2) such that for all f in C_c(R^2) λf= ∫_R^2 f dµWhat is \(\displaystyle \displaystyle \mu \) representing?

- - - Updated - - -

λf=∫(from R to Riemann) f(tt)dt for all f in C_c(R^2).The unique positive regular measure on B(R^2) such that for all f in C_c(R^2) λf= ∫_R^2 f dµ

- - - Updated - - -

The unique positive regular measure on B(R^2) such that for all f in C_c(R^2) λf= ∫_R^2 f dµ

- Admin
- #4

- Jan 26, 2012

- 4,191

I could be wrong, but it seems to me that this question could be answered much more easily (that is, intuitively) by thinking about the corresponding Riemann integral. It's a fact that if the function is Riemann integrable, then

$$\int_{ \mathbb{R}^{2}} f \, dA = \int_{ \mathbb{R}^{2}} f \, d\mu.$$

So take an example, and make $f$ really simple, say $f=1$. Then your integral is simply computing area. Your new measure, $\sqrt{2} \mu$, simply multiplies your area by $\sqrt{2}$, since constants pull out of integrals (at least, they pull out of Riemann and Lebesgue integrals). What is going on geometrically for that to happen?