# THE TRAPEZOIDAL RULE

Consider the graph below.

If there are **n** vertical strips then there are **n+1** vertical lines(ordinates) bounding them.

The limits of the integral are between **a** and **b**, and each vertical line has length **y _{1} y_{2} y_{3}... y_{n+1}**

Therefore in terms of the all the vertical strips, the integral is given by:

approx. integral = (strip width) x (average of first and last y-values, plus the sum of all **y** values between the second and second-last value)

State the values of y for the graph y = x^{2} from 3 to 8.