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#