## Tuesday, October 8, 2013

### Definite integral

# This program calculates the area between two functions the parameters functions, boundaries are hardcoded but they are highlighted for you to change

font "arial", 15,100
graphsize 500,500
fastgraphics
# Choose the dimentions of the graph#############
xmin=-5
xmax=5
ymin=-5
ymax=5
##########################################
y1=0:y2=0
tx=500/(xmax-xmin)
ty=500/(ymax-ymin)
for y = ymin to ymax
for x = xmin to xmax
circle tx*x-xmin*tx, ty*y-ymin*ty,3
if y=ymax+ymin then text tx*x-xmin*tx-15, ty*y-ymin*ty,x
if x=0 then text tx*x-xmin*tx-15, ty*y-ymin*ty,-y+ymax+ymin
next x : next y
line -xmin*tx,0,-xmin*tx,500 : line 0,500+ymin*ty,500,500+ymin*ty
rem generate area
#Choose the x boundaries#####################
bound1=-2
bound2=2
#########################################
area=0
range=bound2-bound1
dx=.01
for x = xmin to xmax step dx
xg= tx*x-xmin*tx
color red
p1=y1
#Equation1 red#############################
y1=x^2
#########################################
yg1= 500-ty*y1+ty*ymin
circle xg, yg1,1
color blue
p2=y2
#Equation2 blue###########################
y2=x-2
########################################
yg2= 500-ty*y2+ty*ymin
circle xg, yg2,1
if x<= bound2 and x>= bound1 then
color darkgreen
area=area+((y1+p1)/2-(y2+p2)/2)*dx
if int(xg+1)/2 = int(xg/2+1) then line xg,yg1,xg,yg2
fill= 255*(x-bound1)/range
end if
next x
refresh
input "press a key",a
text 20,20,"Area="+area
refresh