The rectangular rules for numerical integration are illustrated in Fig. P2.2-1. The left-side rule is depicted in Fig. P2.2-1(a), and the right-side rule is depicted in Fig. P2.2-1(b). The integral of x(t)

is approximated by the sum of the rectangular areas shown for each rule. Let y(kT) be the numerical integral of x(t), 0≤t ≤ kT.

x(1) A x(1) (a) KT (k+ 1)T I x(k) x(k+1) (b) x(k+1) kT (k+ 1)T FIGURE P2.2-1 Rectangular rules for integration: (a) left side; (b) right side.