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Current time:0:00Total duration:2:21

Video transcript

so we have the graph of y equals f of X right over here and what we want to do is figure out the limit of f of X as X approaches negative 4 so what does that mean well a limit is saying what is my function approach as the input of that function approaches in this case negative 4 as the input approaches a value and as we see in this example the function doesn't necessarily have to be even defined at that value we can see F of negative 4 you go to x equals negative 4 and you see that F of negative 4 is undefined so this is not defined but as we'll see even though the function isn't defined there the limit might be defined there and actually it could go the other way around sometimes a function is defined there but the limit is not and we'll see that in future videos but let's just get an understanding here what's going on as X approaches negative 4 as X approaches negative 4 from values greater than negative 4 and from values less than negative 4 well let's first think about values greater than negative 4 so when X is negative 1 this is f of negative 1 this is f of negative 2 this is f of negative 3 this is F of negative 3 point 5 this is F of negative 3 point 9 this is F of negative 3 point 9 9 this is F of negative 3 point 9 9 9 9 9 9 and so you can see the value of our function as X gets closer and closer to negative 4 from values greater than negative 4 seems to be approaching 6 and let's see if that's true from the other direction some from values less than negative 4 so this is f of negative 7 f of negative 6 this is f of negative 5 looks around 7 this is F of negative 4 point 5 F of negative 4 point 1 F of negative 4 point 0 1 F of negative 4 point 0 0 0 0 1 it looks like it's getting awfully it's going to be a little bit more than 6 so it seems as we get closer and closer to 6 as we get closer and closer to x equals negative 4 the value of our function is approaching positive six