Finding area between 2 curves

So I am trying to figure out a code which does the following:

Gets 2 functions from the user

finds out the area of intersection no matter how many finite intersections

you do not have to specify what is the upper and lower curve

fills in the area with a specific colour

Code: What it doesnt do is figure out how to find out upper and lower curve on its own plus doesnt do it for multiple intersections

clc
clear
syms x
y1=input('enter the upper curve as a function of x : ')
y2=input('enter the lower curve as a function of x : ')
t=solve(y1-y2);
t=double(t);
a=int(y1-y2,t(1),t(2))
d=[t(1)-0.2 t(2)+0.2]
ez1=ezplot(y1,d);
set(ez1,'color','r')
hold on
ez2=ezplot(y2,d);
legend('y1','y2')
xv=linspace(t(1),t(2));
y1v=subs(y1,x,xv)
y2v=subs(y2,x,xv)
x=[xv,xv];
y=[y1v,y2v];
fill(x,y,'g')
grid on

Answer 1

[Shubham Rawat]

Hi Sacchin,

I have reproduce your code and I have made some changes such that it work for all intersections. For upper and lower functions they may vary. So i used fill command 2 times to overcome that.

syms x
y1 = input("enter upper function of x: "); %here i used x^3
y2 = input("enter lower function of x: "); %here i used x

t = solve(y1 - y2);
t = double(t);

%changes below
d = t;
d(1) = d(1)-0.2; %subtract 0.2 in first
d(end) = d(end)+0.2; %add 0.2 in last

ez1 = ezplot(y1,d);
set(ez1, 'color', 'r')
hold on
ez2 = ezplot(y2,d);
legend('y1','y2');

xv = linspace(t(1),t(end)); %changes here first to last
y1v = subs(y1,x,xv);
y2v = subs(y2,x,xv);

%fill command using  twice to fill all areas
x = [xv,xv];
y = [y1v,y2v];
fill(x,y,'g');
y = [y2v,y1v];
fill(x,y,'g');
grid on;

Hope this Helps!

[Sacchin Sundar]

Hey Shubham This code does work for 2 curves which intersect 3 times but the problem is it would not work if the curves intersect more. I was not able to figure out how to fill inside a for loop