Let $g$ be Riemann integrable on $[a,b]$, $f(x)=\int_a^xg(t)dt$ for $x∈[a,b]$.
How to show that the total variation of $f$ is equal to $∫_a^b|g(x)|dx$?
closed as off topic by Douglas Zare, Willie Wong, Pietro Majer, Michael Renardy, George Lowther Jun 2 '12 at 10:51
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