Question

integrate x^(1/2)e^x.dx from 0 to 4, n=12
1) the trapezoidal rule

Answer 1

You will need to calculate f(x) at thirteen points: x = 0, 1/3, 2/3, 1, 1 1/3, ... 3 2/3 and 4. The width of each trapezoid is h = 1/3.

Add up the values of f(x) at each point except the endpoints, add
[f(0) + f(4)]/2 to that, and multiply by h.