00:01
I think the first thing i would do is graph these two functions.
00:04
And let me just start with a graph of 3 to the x, because its exponential growth looks something like that.
00:10
So what happens if you have g of x, i'm doing this in red, as 3 to the negative x power, is it reflects over the y -axis.
00:20
And what's different about that when you talk about f of x, which is 3 to the negative x minus 2 and then plus 1.
00:33
And i'm just looking at my graphing calculator real quick, because on this graph, it's hitting at 0, 1.
00:44
But on the other graph, that's actually going to be, i kind of want to just write it right here, f of x is equal to 3 to the negative x minus 2, and then minus 1 is taking this point and actually just shifts it a little up 2, up 1.
01:01
So it's going to hit the ordered pair negative 2, 2.
01:06
It doesn't look much different, but it is very different.
01:11
And that's a graph of f of x.
01:16
So to answer those questions then, i kind of just said it.
01:20
The graph of g to the graph of 1, it's just two shifts, left 2 and, wait, is it minus? i thought it was plus.
01:36
Yeah, i just calculated it down wrong.
01:43
So then the second question, write down the sets that represent the domain and range of f.
01:49
Ok, so the domain is all reals.
01:52
And i'm a big fan of integral notation, so i write it like this.
01:56
And then range is all values for y that are bigger than 1.
02:02
May i write that off to the side in case you've never seen this notation before.
02:07
The domain is all reals, and y is greater than 1.
02:11
And the reason why is we have that shifting up 1, and our horizontal asymptote is at y equals 1.
02:19
And those are your answers for f of x, not g of x.
02:23
So then what they want you to do next is take that equation, 3 to the negative x minus 2 plus 1, and equal it to 243, which isn't too bad, because you can subtract 1 over those 244.
02:43
I knew it was going to be 243, which i believe is 3 to the fifth power.
02:50
And that way, the exponents have to be the same now, because the bases are the same.
03:00
And you can add 2 over, but then x would have to equal negative 7.
03:06
And if you type that into your calculator, you can actually look at your table and see that x is negative 7.
03:14
You get 244.
03:17
Ok, i accidentally did f already with this graph over here.
03:27
The only thing i didn't do is draw the horizontal asymptote.
03:30
And i haven't given you the x, the y -intercept either.
03:36
And what you'd have to do is plug in 0 for x.
03:39
And so the y -intercepts, let me just write it down here.
03:45
Y -intercept would be the ordered pair f of 0, which would equate to 3 to the negative second power plus 1, which would equal 3 squared is 9.
03:57
So it's 1 over 9 plus 1, which would be 10 ninths.
04:03
And what's the next question? the equation of the inverse, that's kind of complicated.
04:08
What you have to do is switch x and y...