Example 6.2

1. 1. Initialize variable x as a row vector, from 2 with increments of 0.1 to 5: x=2:.1:5;
2. 2. Declare variable y as y=x^2;. Note the following error prompt : ??? Error using ==> mpower Inputs must be a scalar and a square matrix.
3. This is because x is a vector quantity and MATLAB is expecting a scalar input for y. Because of that, we need to compute y as a vector and to do that we will use the dot operator as follows: y=x.^2;. This tells MATLAB to create vector y by taking each x value and raising its power to 2.
4. 3. Now we can issue the following command to calculate the first area, the output will be as follows:

    area1=trapz(x,y)
area1 =
    39.0050

    x=2:.01:5;
y=x.^2;
area2=trapz(x,y)

area2 =
    39.0001

    x=2:.001:5;
y=x.^2;
area3=trapz(x,y)

area3 =
    39.0000