Finding The Area Between Curves - Texas Instruments TI-86 Manual Book

If necessary, select
ALL-
from the equation editor
menu to deselect all
functions. Also, turn off all
stat plots.

Finding the Area between Curves

Find the area of the region bounded by:
In Func graphing mode, select
enter the equations as shown.
2
y1=300 xà(x +625)
Select from the
WIND
xMin=0 xMax=100
Select GRAPH from the
Select ISECT from the
functions. Press b to select
again to set the current cursor location as the initial guess. The solution uses the solver. The
value of x at the intersection, which is the lower limit of the integral, is stored to
The area to integrate is between
to x=75 . To see the area on a graph, return to the home screen,
select Shade from the
expression:
Shade(y2,y1,Ans,75)
Select from the
TOL MEM
On the home screen, compute the integral with
fnInt(y1Ny2,x,Ans,75)
f(x)=300 xà(x
g(x)=3 cos (.1 x)
x=75
y(x)= from the GRAPH
y2=3 cos (.1 x)
menu and set the window variables as shown.
GRAPH
xScl=10 yMin=L5
GRAPH menu to display the graph screen.
GRAPH MATH menu. Move the trace cursor to the intersection of the
y1 . The cursor moves to
y1 and y2 , from
GRAPH DRAW menu, and execute this
menu and set L5
tol=1
E
fnInt
Chapter 19: Applications
2
+625)
menu to display the equation editor and
yMax=10 yScl=1
. Press b. Then press b
y2
x=5.5689088189
.
( CALC menu). The area is 325.839961998.
245
xRes=1
Ans and x .