Now some enclosed integrals. These are line and surface integrals. A closed line integral is a path that ends Where it begins. A closed surface is an area that wraps ahas no openings. Both are denoted by the circle in the middle of the integral, gds and 933 CM (usually this is just denoted by dA, so watch for the type of integrand). These will be used in Maxwell's equations if the integrand can be simplied to a scalar. 14. (1 + x + x2)ds = along the square path of length 5 starting at x=1 and contained in the rst quadrant. Remember x will be constant along the vertical paths. 5