22.07.2014 Views

Lecture 4 - Computer Science Department - University of Kentucky

Lecture 4 - Computer Science Department - University of Kentucky

Lecture 4 - Computer Science Department - University of Kentucky

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

Lower and Upper Sums<br />

The lower sums and upper sums <strong>of</strong> f corresponding to the given partition<br />

P is<br />

n−11<br />

L(<br />

f ; P)<br />

= m x − x<br />

U<br />

(<br />

f<br />

;<br />

P<br />

) =<br />

∑<br />

i=<br />

0<br />

n−1<br />

∑<br />

=<br />

i=<br />

0<br />

i<br />

M<br />

( )<br />

i+<br />

1<br />

( x<br />

x<br />

)<br />

i+ 1 −<br />

If we consider the definite integral <strong>of</strong> a nonnegative f as the area under<br />

the curve, we have<br />

L ( f ; P)<br />

f ( x)<br />

dx ≤ U(<br />

f ; P)<br />

for all partitions P<br />

∫<br />

≤ b a<br />

i<br />

i<br />

i<br />

If f is continuous on [a,b], then the above inequality defines the definite<br />

integral. The integral also exists it if f is monotone (ith (either increasing i or<br />

decreasing) on [a,b]<br />

6

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!