Area between two points and a curve

Hi All,

I want to find the area between a curve and two points. The equation is:

>> syms x

>> x4=1.18:0.0000001:3;

>> y4=-2*exp(-(x4).^2);

>> graph4= plot(x4,y4);

I want the area to the left hand side! points: (1.18,-0.5) and (1.18,0).

Any thoughts?

Thank you

A

Answer 1

[Stephan]

Hi,

the whole area of your figure is a rectangle with area: (3-1)*(0-(-0.5).

If you calculate the integral of your curve in the bounds f(×)=-0.5 (find corresponding x (=1.18(?))) and x=3, you can subtract both values from eachother and you get the green marked area.

Best regards

Stephan

[Bristol19]

Briliant Stephan,

It was a massive help! Thank you

Happy new year in adance! :-)

H

[Stephan]

please make sure to accept useful answers.

Answer 2

[madhan ravi]

https://www.mathworks.com/matlabcentral/answers/180829-shade-area-between-graphs#answer_169649 - just simply use trapz() to calculate area

[Bristol19]

Hey Madhan,

Thank you but I could not follow the same way they did it. As I only have one function(curve).

Thank you

H