SITUATION 2 The error function erf(a) is defined as erf (a) = 2 So exp (-x²) dx Determine erf(1) using: 0 (a) composite trapezoidal rule, h = 0.1 (b) composite Simpson's 1/3 rule, h = 0.1 (c) Romberg interpolation, with error tolerance of 0.5% (d) Gauss-Legendre quadrature, n = 4