How do you graph the function #6xy = 13#?

1 Answer
Aug 31, 2015

Note that #x# and #y# must either both be positive or both be negative; as one of them approaches #0# the other approaches (an appropriately signed) #oo#. Pick and plot a few sample data points.

Explanation:

#6xy = 13color(white)("XXX")rArrcolor(white)("XXX")xy=13/6#

As noted in the answer (above) neither #x# nor #y# can equal #0# (#rArr# the asymptotes are the X and Y axes).

The points on the curves closest to the origin will occur when #x=y#
#color(white)("XXX")rArr# at #(sqrt(13/6),sqrt(13/6))# and #(-sqrt(13/6),-sqrt(13/6))#
#color(white)("XXXXXXXXXXXXXXXXXXX")#Note: #sqrt(13/6)# is approximately #1.47#

It is difficult to find "nice" (i.e. integer) points to plot.

However note that #x# and #y# are symmetric. If #(a,b)# is a solution pair, then so are #(b,a)#, #(-a,-b)#, and #(-b,-a)#

#color(white)("XXX"){: (a," ",b), (1," ", 2 1/6), (2," ",1 1/12), (3," ",13/18) :}#
graph{6xy = 13 [-5.546, 5.55, -2.78, 2.77]}