Let be a first-quadrant point on , and consider the vertical line segment PQ shown in the figure. (a) If PQ is rotated about the y-axis, determine the volume V of the resulting cylinder. (b) For what point with is the volume V in part (a) the same as the volume of the cylinder of radius 1 and altitude 5 shown in the figure?

Section 2.1 Addition of Matrices and Scalar Multiplication Notation a11a 12a 13 … 1n a21a 22a 23 … 2n = aa a a … 31 32 33 3n A= a()ij ▯▯▯ ▯ am1m3 mna m … In order to add matrices, add corresponding entries. For the operation to be defined, they must be the same size. The sum will also be the same size. If the matrices are not the same size, then the operation is undefined. 2 − + Example: 3 8 Add corresponding entries