The dimension of following cuboid is:
5 units x 3 units x 2 units
2 units x 1 unit x 2 units
2 units x 2 units x 2 units
1 unit x 1 unit x 1 unit
The area bounded by the curves f(x) = x2 + 1 and g(x) = x - 1 on the interval [1,3] is: