Question #b39ee

2 Answers
Jan 29, 2018

#- 1/(2a)#

Explanation:

graph{2/x [-10, 10, -5, 5]}

if #x = 4#, then #g(x)# = #g(4)#

= #2/4# = #1/2#

and when #x = a#, then #g(x)# = #g(a)#

= #2/a#

So, average rate of change of g(x) respect to x (actually limit of this

is the derivative of that function)

= #(Deltag(x))/(Delta x)# = #(1/2 - 2/a)/(4 -a)# = #(cancel(a- 4)/(2a))/cancel(-(a - 4))# = #(1/(2a))/-1# = #-1/(2a)#

Hope this helps.

Jan 30, 2018

#m=(4-a)/(2a^2-8a)#

#m=-1/(2a)#

Explanation:

Remember that the formula for finding the average rate of change between the two points is #(y_2-y_1)/(x_2-x_1)#

We can get our #y# coordinate by plugging the #x# values into the function.

Our coordinate would be #(4,g(4))# and #(a,g(a))#

We now calculate the #y# values.

When #x=4,#
#g(4)=2/4=>g(4)=1/2#
Our first point is at #(4,1/2)#

Similarly, when #x=a#,
#g(a)=2/a#

Our second point is at #(a,2/a)#

We now use our formula.

#m=(2/a-1/2)/(a-4)#

We try to simplify this.

#m=(2/a-1/2)/(a-4)#

=>#m=(4/(2a)-a/(2a))/(a-4)#

=>#m=((4-a)/(2a))/(a-4)#

=>#m=(4-a)/(2a)*1/(a-4)#

=>#m=(4-a)/(2a)*1/(-4+a)#

=>#m=(4-a)/(2a)*(-1)/(4-a)#

=>#m=cancel(4-a)/(2a)*(-1)/cancel(4-a)#

=>#m=1/(2a)*-1#

=>#m=-1/(2a)#

That is our answer!

You may get #m=(4-a)/(2a^2-8a)# if you did the following:

#m=(4-a)/(2a)*1/(a-4)#

=>#m=(4-a)/((2a)(a-4))#

=>#m=(4-a)/(2a^2-8a)#