10 SCREEN 12
20 WINDOW (-1, 3)-(28, -20)
30 LINE (0, 1)-(2, 1)
40 LINE (2, 1)-(2, 0)
90 LINE (-1, 0)-(5, 0)
100 LINE (0, 5)-(0, -1)
110 PAINT (.5, .5)
115 LOCATE 1, 20
120 PRINT "Double Integral"
130 LOCATE 3, 10
140 PRINT "y=1"
150 LOCATE 5, 10
160 PRINT "x=2"
170 PRINT " "
180 PRINT "Find the mass of rectangle 0<=x<=2,0<=y<=1 with mass density m=xy^2"
190 PRINT CHR$(244); "1"; CHR$(244); "2          "; CHR$(244); "1             "; CHR$(179); "x=2"
200 PRINT CHR$(245); "0"; CHR$(245); "0 xy^2dxdy="; CHR$(245); "0 (x^2/2)y^2dy"; CHR$(179); "x=0"
210 PRINT " "; CHR$(244); "1                "; CHR$(179); "1"
220 PRINT "="; CHR$(245); "0 2y^2dy=(2y^3)/3"; CHR$(179); "0 =2/3"
230 PRINT "So the mass is 2/3"
240 PRINT " "
250 PRINT "PRESS ANY KEY TO CONTINUE"
260 WHILE INKEY$ = "": WEND
270 SYSTEM