Floor of m+n-1 over n/Example 1

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Example of use of Floor of $\frac {m + n - 1} n$

Let $n \in \Z$.

Then:

$\floor {\dfrac {n + 2 - \floor {n / 25} } 3} = \floor {\dfrac {8 n + 24} {25} }$


Proof

\(\ds \floor {\dfrac {n + 2 - \floor {n / 25} } 3}\) \(=\) \(\ds \floor {\dfrac {\paren {n - \floor {n / 25} } + 3 - 1} 3}\) rearrangement
\(\ds \) \(=\) \(\ds \ceiling {\dfrac {n - \floor {n / 25} } 3}\) Floor of $\dfrac {m + n - 1} n$
\(\ds \) \(=\) \(\ds \ceiling {\dfrac {n + \ceiling {-n / 25} } 3}\) Ceiling of Negative equals Negative of Floor
\(\ds \) \(=\) \(\ds \ceiling {\dfrac {\ceiling {n - n / 25} } 3}\) Ceiling of Number plus Integer
\(\ds \) \(=\) \(\ds \ceiling {\dfrac {\ceiling {24 n / 25} } 3}\) simplification
\(\ds \) \(=\) \(\ds \ceiling {\dfrac {8 n} {25} }\) Ceiling of $\dfrac {x + m} n$: Corollary
\(\ds \) \(=\) \(\ds \floor {\dfrac {8 n + 25 - 1} {25} }\) Floor of $\dfrac {m + n - 1} n$
\(\ds \) \(=\) \(\ds \floor {\dfrac {8 n + 24} {25} }\) simplification

$\blacksquare$


Sources