# Lsub3 and Usub3 for function

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• December 5th 2012, 05:31 AM
chizmin10
Lsub3 and Usub3 for function
Find L3(f) and U3(f) for the function f(x) =1/(x+1)and the interval
[a,b] = [0,3].
• December 5th 2012, 05:37 AM
Plato
Re: Lsub3 and Usub3 for function
Quote:

Originally Posted by chizmin10
Find L3(f) and U3(f) for the function f(x) =1/(x+1)and the interval [a,b] = [0,3].

Please define $L_3(f)~\&~U_3(f)$. Please give an exact definition.
• December 5th 2012, 06:00 AM
chizmin10
Re: Lsub3 and Usub3 for function
The U is the n-th upper sum for f and the L is the n-th lower sum for f.
• December 5th 2012, 06:57 AM
Plato
Re: Lsub3 and Usub3 for function
Quote:

Originally Posted by chizmin10
The U is the n-th upper sum for f and the L is the n-th lower sum for f.

Draw a graph. You will see that the function is decreasing on $[0,3]$.

That means that an upper sum is a left-hand sum and a lower sum is a right-hand sum.

Because $n=3$ we have $\Delta x=1$.