DEFDBL A-Z
DEF fnf (x) = SQR(1 + x ^ 3)
a = 1
b = 3
numberofsteps = 4
deltax = (b - a) / numberofsteps
x = a
accumulation = 0
FOR k = 1 TO numberofsteps
        deltaS = fnf(x) * deltax
        accumulation = accumulation + deltaS
        x = x + deltax
        PRINT deltaS, accumulation
NEXT k