Texas Instruments Voyage 200, User Manual

Page: 763 / 1008

Activities 763
3. Use the
abs( )
function to find the absolute
value of
f(x+y
i
)
.
(This calculation may take about 2
minutes.)
Note:
The absolute value of a function
forces any roots to visually just touch
rather than cross the
x
axis. Likewise, the
absolute value of a function of two
variables will force any roots to visually
just touch the
xy
plane.
4. Copy and paste the last answer to the
entry line and store it in the function
z1(x,y)
.
Note:
The graph of
z1(x,y)
will be the
modulus surface.
5. Set the unit to 3D graph mode, turn on the
axes for graph format, and set the
Window variables to:
eye= [20,70,0]
x=
[ L 2,2,20]
y= [ L 2,2,20]
z= [ L 1,2]
ncontour= [5]