Can someone show me how to find upper and lower sums and hence solve definite integral of x^3 for [0,2]
thanks
Do your class notes or textbook contain no reference material? Try reading this: http://www.geometer.org/mathcircles/riemannint.pdf
Use the example as a model for integrating x^3 over [0, 2]. If you're still stuck, please show what you've tried and where you get stuck.
No. I would guess that you have derive the lower sum along the same lines that you derived the upper sum. Then take the limit as n --> oo of either one of them.
By the way, when asking a question you should post what you've been able to do so that people don't spend their time posting things that you already know.