Boas Mathematical physics book, definition of center of mass

[fluidistic]

In Boas' book I can read that the definition of center of mass of a body has coordinates x_{CM}= \int x_{CM}dM= \int x dM.
Shouldn't it be this same integral but divided by M?!
Also, I didn't find the definition of center of mass for particles or any non continuous bodies.
I'd be grateful if someone could point me what I'm missing.

Edit: I forgot to say it's on page 210 in the 2nd edition.

 

[WiFO215]

x_{CM}= \int x_{CM}dM

How could this be true? The second equality is correct. Since x_CM is a constant, you can pull it out of your integral. There's your missing M. You'll thus have x_CM = integral(stuff)/M

For discrete objects, it is just a weighted mean of the positions. Should be in there somewhere!

 

[fluidistic]

How could this be true? The second equality is correct. Since x_CM is a constant, you can pull it out of your integral. There's your missing M. You'll thus have x_CM = integral(stuff)/M

For discrete objects, it is just a weighted mean of the positions. Should be in there somewhere!

My bad, I misunderstood the book. The first equality is wrong and the second is right as you said. Now I get it. Thanks a lot.
Yeah I know how to calculate the center of mass of discrete objects. I just wanted to be sure and referred to the book but couldn't find it (still didn't find it).

 

[WiFO215]

If that is so, then simply substitute in the density of the object delta functions for those mass points and the continuous reduces to the discrete ;)