Evaluating the area between two curves.
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how to Evaluate the area between two curves using matlab? for example this one y=x^2 and y=2*x
2 Comments
kalash vasaniya
on 8 Nov 2021
Find the area of the region bounded by the curves x=y^3 and x=y^2 in matlab
Walter Roberson
on 8 Nov 2021
syms x y
fimplicit([x == y^3, x == y^2], [-1 10])
Which of the two areas? The right-hand one is obviously unbounded, but your instructions do not say to do only the other area.
And please explain how your instructions will solve the question asked 10 years ago by Ejay Kasai ??
Answers (2)
Grzegorz Knor
on 12 Sep 2011
In your case:
syms x
x0 = eval(solve('x^2 -2*x'));
x = linspace(x0(1),x0(2),100);
y1 = x.^2;
y2 = 2*x;
fill([x x(end:-1:1)],[y1 y2(end:-1:1)],'r')
hold on
plot(x,y1,x,y2,'LineWidth',2)
grid on
a = trapz(x,y2)-trapz(x,y1);
Instead of:
syms x
x0 = eval(solve('x^2 -2*x'));
You can use:
x0(1) = fzero('x.^2 -2*x',1);
x0(2) = fzero('x.^2 -2*x',1.5);
6 Comments
Walter Roberson
on 13 Sep 2011
The expression Grzegorz gave, a = trapz(x,y2)-trapz(x,y1) *is* the code to evaluate the area between the two curves. This is elementary calculus: the area between two curves is the difference between their integrals. trapz() calculates numeric integrals.
Shyam babu
on 8 Jul 2023
find the area included between the curves y^2=4*x & x^2=4*y
1 Comment
Walter Roberson
on 8 Jul 2023
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