Find the circumference of the given circle a diameter of 40m use 3.14 as an approximation of pi A 120cm
B 100 cm
C 125.6 cm
D 40 cm

The variable z is directly proportional to x, and inversely proportional to y. when x is 4 and y is 13, z has the value 1.2307692307692. what is the value of z when x= 9, and y= 20

Determine whether the following statements are true and give an explanation or counterexample. bold a. when using the shell method, the axis of the cylindrical shells is parallel to the axis of revolution. bold b. if a region is revolved about the y-axis, then the shell method must be used. bold c. if a region is revolved about the x-axis, then in principle it is possible to use the disk/washer method and integrate with respect to x or the shell method and integrate with respect to y.

Acylinder and its dimensions are shown. which equation can be used to find v, the volume of the cylinder in cubic centimeters?