I cannot calculate at Integration of mass.
It is impossible that integration by parts,Integration by substitution、and It asks for volume by integration.
To a test, there is nothing for a while.
So I study an impossible place .
I do my best.
I cannot calculate at Integration of mass.
It is impossible that integration by parts,Integration by substitution、and It asks for volume by integration.
To a test, there is nothing for a while.
So I study an impossible place .
I do my best.