How do I calculate Reimans Sums when n is very large? I can use an applet for simple functions but when I use an applet with a more complex function the applet does understand the input. If I have the function 2x^3 + 2 cos(x/2) - (1.2) ^x and I want to find the integral whichI calculated is ((5/6)^(-x)LN(5/6) - SIN(x/2) + 6x^2) how could I Find the average value for the particular solution on the interval [0, 2/3] and check the average value with a reiman sum?