00:01
Okay, so we're going to be stating the domain range of this function and then graphing it.
00:04
So the domain is all of the x values that give us a defined y value or that when we plug in that x value, we actually get a value back for y that is a real number.
00:16
And so in this case, 2 to the x, we can actually plug in any real number for x and we'll get a real value back for y.
00:23
So our domain here is going to be from negative infinity to infinity.
00:27
And the reason for that is because the function, or the exponential function, 2 to the x, there are no x values in the real numbers that if we plugged it in, we would get an undefined function back.
00:37
And so because of that, our domain is all real numbers.
00:41
The range is going to be all the y values that our x values can produce.
00:45
So for all of the x values that we plug into our function, what is the range of y values that we get back? the important thing to notice here is that 2 to the x, it's an exponential function.
00:56
And exponential functions never are going to have a negative, we're never going to get a negative value back for that exponential function.
01:05
And because of that, this 2 to the x value is always going to be positive.
01:09
And then we're multiplying it by a negative number here.
01:12
And so we're always actually going to get a negative value for this negative 1 times 2 to the x.
01:17
So our range is going to include all of the negative numbers.
01:20
The only thing is it's also going to include positive numbers, and it's going to include positive numbers up to, the number positive 3.
01:28
And the reason for that is because exponential functions, whenever we raise a number to an exponent, we can always guarantee that we're never going to get a value equal to zero back.
01:38
We're equal to exactly zero.
01:40
And it might be very close to zero, but we're never going to get a value equal to exactly zero back.
01:45
So that means that the lowest value we can get here for this negative 1 times 2 to the x is a value almost equal to zero, which means the highest value for our range is going to be three.
01:57
However, we're not including it, since we don't actually have a value for our function where we're going to get negative 1 times 2 to the x equaling 0, so we don't include 3.
02:07
And so this is our domain and range.
02:09
Now we just want to graph our function.
02:13
So i'm just going to plot, we're just going to be doing, let's do five points here...