# Area under curve

• Apr 24th 2010, 03:16 AM
alis88
Area under curve
Hello,

Please could someone show me how to find the area between the "Loading trendline 1" line and the x-axis?

Please could you also show me how to find the area under the "Unloading trendline 1" line?

Assume both lines extend to the top of the graph area.

Thank you in advance.
• Apr 24th 2010, 05:58 AM
Gusbob
Quote:

Originally Posted by alis88
Hello,

Please could someone show me how to find the area between the "Loading trendline 1" line and the x-axis?

Please could you also show me how to find the area under the "Unloading trendline 1" line?

Assume both lines extend to the top of the graph area.

Thank you in advance.

A simple way would be to find the point of intersection first - say (a,b). Let loading trendline = T1, unloading trendline = T2. Then then take

$\int_0^a T1\,\, dL - \int_0^a T2 \,\,dL$

Essentially this takes the area under the top graph - area under bottom graph. The remaining numbers should be the area between the two graphs.