I don't think anyone in this forum will do your work for you ;-), but here's a hint: For every two consecutive points, calculate the area of the trapezoid generated by the two points and the corresponding points on the X axis. Add up the (signed) areas, and you have your total area. By signed, I mean that that the area should be positive when going from left to right and negative when going from right to left, or vice versa. The sign of the calculated area will depend on the orientation of your curve.
Probably some of the integration VIs can do the trick as well, at least for some special cases.
