\START82\
\COMMENT=Program file dated 12/04/95, 15:54
\NAME=SURFAREA
\FILE=SURFAREA.82P
ClrHome
Disp "FIRST ENTER \Y1\"
Disp ""
Disp "THEN HIT ENTER"
Pause 
ClrHome
Func
Lbl 1
ClrDraw
ClrHome
Disp "LOWER LIMIT"
Disp "OF X"
Prompt L
Disp "UPPER LIMIT"
Disp "OF X"
Prompt U
Disp "HOW MANY"
Disp "INTERVALS ?"
Prompt N
0\->\S
(U-L)/N\->\W

L\->\Xmin
U\->\Xmax
L\->\T
ClrHome
Disp "SCALING GRAPH"
Disp "PLEASE WAIT"
fMin(\Y1\,X,L,U)\->\A
fMax(\Y1\,X,L,U)\->\B
\Y1\(A)\->\Ymin
\Y1\(B)\->\Ymax
If abs (Ymin)>abs (Ymax)
Then
abs (Ymin)\->\Ymax
Else
\(-)\(Ymax)\->\Ymin
End
DispGraph
For(I,1,N)
\Y1\(T)\->\P
\Y1\(T+W)\->\Q


S+(2\pi\((P+Q)/2)\sqrt\(W\^2\+(Q-P)\^2\))\->\S
Line(T,\(-)\P,T,P)
Line(T,P,T+W,Q)
Line(T+W,Q,T+W,\(-)\Q)
Line(T+W,\(-)\Q,T,\(-)\P)
T+W\->\T
End
Pause 
ClrHome
Disp "INTEGRAL ="
Disp S
Disp ""
Disp "RUN AGAIN ?"
Disp "(1) YES"
Disp "(2) NO"
Input R
If R=1
Goto 1
ClrHome
\STOP82\