00:01
All right, so they give us this function of the number of smartphones and tablets used in a year for t going from one to three.
00:08
And the most important thing they say is that one corresponds to the year 2010.
00:12
The whole thing is 2010 through 2012.
00:15
And they ask a couple questions about 2011.
00:18
So that must mean that t was two then.
00:22
So first they ask how many smartphones and tablets in 2011? so we're looking for f of 2.
00:30
128 .1 times 2 to the 1 .94.
00:35
Okay, and then we just need to type that into our calculator.
00:39
Do you make sure every time you type into a calculator that the parentheses are going in the right place, otherwise you might get a vastly different answer than what you're looking for.
00:49
So we get 491, let's round it a little bit so that these decimals don't go on forever.
00:57
If you just write approximately equal, when you round.
01:01
And this is in millions.
01:04
So about 491 .53 million smartphones and tablets in 2011.
01:16
So that's a lot.
01:17
And then we want to find how fast the number was changing...