floating point formula, error bound for rounding and chopping Richardson extrpolation for trapezoidal Simpson's proof Peano's error formula hw on simpson's periodic function, rate of convergence implement Richardson recursively. cancelation and extra order of accuracy for integration implement/apply Richardson extraplation analytically, then numerically. Fact: u''= f = sin(\pi x), u(0)=u(1)=0 the solution can be obtained by the following formula u(1/2) = \int g(x,\xi) f(\xi) d \xi