DEFDBL A-Z
DEF fnf (x) = x ^ 2
xinitial = 0
xfinal = 1
n = 2
deltax = (xfinal - xinitial) / n
FOR k = 1 TO n
        xl = xinitial + (k - 1) * deltax
        xr = xinitial + k * deltax
        yl = fnf(xl)
        yr = fnf(xr)
        segment = SQR((xr - xl) ^ 2 + (yl - yr) ^ 2)
        total = total + segment
        'PRINT k, segment
NEXT k
PRINT n, total