Posted by Yania on Saturday, April 6, 2013 at 6:11pm.
a function f(x) is defined as f(x)= 8x^2. What is f(3)?

math  Leo, Saturday, April 6, 2013 at 6:37pm
All you need to do is substitute 3 in place of the x.

math  Ollie, Saturday, April 6, 2013 at 6:39pm
substitute 3 for every x in f(x) and simplify.

math  Steve, Sunday, April 7, 2013 at 6:21am
by now you've probably done it, but watch the "" signs carefully
f(3) = 8 * (3)^2 = 8(9) = 72