00:02
In this question, we are asked to find the domain of the function f.
00:05
In other words, we are asked to find the values of x which we can plug in in the function f for x, and the function would make sense.
00:15
So, but it's much easier to find the values of x for which the function doesn't make sense.
00:23
To do that, we need to rewrite the function f as x plus 4 divided by x minus 7 times a x.
00:32
X plus 7 using the difference of squares formula.
00:38
Now, note that if you choose x equals 7, you're going to get 11 divided by 0 multiplied by 11, sorry, by 14.
00:55
Well, that's not good because we are dividing by 0.
01:01
And this means that 7 is not in the domain...