How can I draw this ellipse on MatLab

I need to draw this ellipse on Matlab and i can't. My problem seems to be with the plus-minus symbol.

I don't know how to set my axis to get my ellipse right in the middle of my graph !?

It need to be in :

Y = (0:10)

X = (0:8)

This is what i've done so far :

x=0:0.001:8;

y= (((5*(4+-sqrt(8*x-x.^2)))/4));

plot(x,y);

grid on;

I'm using Matlab R2013a

From a student who need your help please !!!!!!

PS : sorry for the silly mistakes, i'm not an anglophone !!

[per isakson]

Your code produces half an ellipse.

Matlab doesn't interpret +-sqrt the way you intend.

You can make it two cases and finally concatenate them.

Answer 1

[Roger Stafford]

It's easiest to generate an ellipse parametrically. I deduce from your equation for y that the ellipse's equation is:

 (x-4)^2/4^2 + (y-5)^2/5^2 = 1

This can be represented parametrically using the parameter t by:

 t = linspace(0,2*pi);
 x = 4 + 4*cos(t);
 y = 5 + 5*sin(t);
 plot(x,y)
 axis equal

[Image Analyst]

Mathieu, see the FAQ : http://matlab.wikia.com/wiki/FAQ#How_do_I_create_an_ellipse.3F (essentially the same as Roger's code, but there's other good stuff in there that you may like to see and you may benefit from).

Answer 2

[Mathieu Bouchard]

Thank you Roger Stafford !!!!

This is exactly what I needed !

Isakson : that was my problem but i'm new on matlab and I don't know all the function of it and how to dot it !