7102 Upper & Lower Sum
by EngliSea on 2020-07-16
ᐥThe upper sum of a function f relative to a partition P is defined by 「sup(f(x))ƧP[a,b]」
The lower sum of a function f relative to a partition P is defined by 「inf(f(x))ƧP[a,b]」.ᐥ


U(P) = 「S⸤i⸥(x⸤i⸥−x⸤i−1⸥) Σi=0,n」
where S⸤i⸥ = sup{f(x):x⸤i−1⸥≤x≤x⸤i⸥}
L(P) = 「I⸤i⸥(x⸤i⸥−x⸤i−1⸥) Σi=0,n」
where I⸤i⸥ = inf{f(x):x⸤i−1⸥≤x≤x⸤i⸥}