Basic Ring Theory - 20 (On Flatness)
Posted: Fri May 20, 2016 10:27 pm
Show that flatness is preserved under "base change" (extension of scalars), i.e. show that if $f \ \colon A \longrightarrow B$ is a ring homomorphism and $M$ is a flat $A$-module, then $M_{B} = B \otimes_{A} M$ is a flat $B$-module.