To find the volume of this solid of revolution, use the meat-slicer method:[br][br][br]1.  Find an expression that represents the area of a random cross-section of the solid (in terms of [i]x[/i]). This cross-section is a circle with a radius of 2 sin [i]x[/i][i]:[br][/i][img width=212,height=33]https://www.dummies.com/wp-content/uploads/312120.image2.png[/img][br][br]2.  Use this expression to build a definite integral (in terms of [i]dx[/i]) that represents the volume of the solid. This time, the limits of integration are from 0 to π/2:[br][img width=116,height=131]https://www.dummies.com/wp-content/uploads/312121.image3.png[/img][br][br][br]3.  Evaluate this integral by using the half-angle formula for sines:[br][br][br][img width=181,height=244]https://www.dummies.com/wp-content/uploads/312122.image4.png[/img][br][br][img width=196,height=128]https://www.dummies.com/wp-content/uploads/312123.image5.png[/img][br][br][br][br]So the volume of this solid of revolution is approximately 9.8696 cubic units