Question #06261

1 Answer
Oct 14, 2017

It is because lim_(x->oo)(1/x)=0

Explanation:

I assume the question is written as:
lim_(x->oo)(6/x)-3

We can first factor out the 6 like so:
lim_(x->oo)(6/x)-3
=lim_(x->oo)(6*1/x)-3
=lim_(x->oo)(6)*lim_(x->oo)(1/x)-3
=6*lim_(x->oo)(1/x)-3

Then, we just solve for:

lim_(x->oo)(1/x)

Recall that the limit of 1/x as x approaches oo is 0.
This is because, for bigger and bigger values of x, 1/x becomes smaller and smaller.

graph{1/x [-4.25, 15.75, -0.56, 9.44]}

You can see on the above graph, that as you go further along the x-axis, the closer the graph gets to 0.

So, the limit of this graph as x approaches oo is 0.

Now, we know that:
lim_(x->oo)(1/x)=0

So:

6*lim_(x->oo)(1/x)-3

=6*0-3

=-3