Make sure your angles are in units of radians (not degrees), where 2π radians = 360 degrees. But after that you will get the ...

The radius of a circle or a sphere is the distance between the center and the edge. The radius can be used to calculate a circle's diameter, area and circumference. Likewise, a sphere's volume is ...

Researchers have made a precise measurement of the size of the proton -- a crucial step towards solving a mystery that has preoccupied scientists around the world for the past decade. The world's ...