area under curve

clc
clear all
close all
syms x
y1=input('ENTER THE Y1 REGION VALUE:');
y2=input('ENTER THE Y2 REGION VALUE:');
t=solve(y1-y2);
%(Y1-Y2=0)
po=double(t)
poi=sort(po)
n=length(poi)
m1=min(poi)
m2=max(poi)

ez1=ezplot(y1,[m1-1,m2+1])
hold on 
TA=0
ez2=ezplot(y2,[m1-1,m2+1]) 
if n>2
    for i=1:n-1
     A=int(y1-y2,poi(i),poi(i+1))
     TA= TA+abs(A)
     x1 = linspace(poi(i),poi(i+1))
     yy1 =subs(y1,x,x1)
     yy2 = subs(y2,x,x1)
    
    %iii)Creating a polygon:
    
    xx = [x1,fliplr(x1)]
    yy = [yy1,fliplr(yy2)]
    fill(xx,yy,'g') 
    grid on 
    end
else
    A=int(y1-y2,poi(1),poi(2))
    TA=abs(A)
    x1 = linspace(poi(1),poi(2));
    yy1 =subs(y1,x,x1)
    yy2 = subs(y2,x,x1)
    xx = [x1,fliplr(x1)]
    yy = [yy1,fliplr(yy2)]
    fill(xx,yy,'g')
end