What is the next fraction in this sequence?
3
6
12
24
6,
18
54
1621

Express the following as a function of a single angle, cos(60) cos(-20) - sin(60) sin(-20)

Pls! does anybody know a shortcut for answering these types of questions in the future?

7. the area of the playing surface at the olympic stadium in beijing isof a hectare. what area will it occupy on a plan drawn to a scaleof 1: 500?