Maximizing Area of an Ellipse Passing Through a Fixed Point

In summary: So I wrote parametrics in what I did can you or anyone help me ??Perhaps you could solve the constraint for either of the two variables and then use substitution to obtain an objective function in one variable...(Thinking)
  • #1
leprofece
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347) An ellipse slmetric with respect to the coordinate axes handle: through the fixed point (h, k). Find The equation of the ellipse's?
area maximum
answer k2/SUP] h 2 + h 2 y 2 = 2 h 2 k2 The equations here must be
y = m(x-h)+k

Parametrizing
x= a cos(t)
y = b(sen(t)

D= (a cost-h)2+((macosth-h)2+ k -k)2

am I right?
Becuse I could not get the right answer
 
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  • #2
leprofece said:
347) An ellipse slmetric with respect to the coordinate axes handle: through the fixed point (h, k). Find The equation of the ellipse's?
area maximum
answer k2/SUP] h 2 + h 2 y 2 = 2 h 2 k2 The equations here must be
y = m(x-h)+k

Parametrizing
x= a cos(t)
y = b(sen(t)

D= (a cost-h)2+((macosth-h)2+ k -k)2

am I right?
Becuse I could not get the right answer

If I understand it correctly, the problem is to find an ellipse symmetric about the coordinate axes and passing through the fixed point $(h,k)$, such that the ellipse has the minimum possible area. (The question says maximum area, but in fact the only critical point is a minimum, and the maximum area is unbounded.)

The equation of the ellipse is $\dfrac{x^2}{a^2} + \dfrac{y^2}{b^2} = 1$, and we have to choose $a$ and $b$ so as to minimise the area of the ellipse, which is $\pi ab.$ The condition for the point $(h,k)$ to lie on the ellipse is $\dfrac{h^2}{a^2} + \dfrac{k^2}{b^2} = 1$, or $a^2k^2 + b^2h^2 = a^2b^2$. So we want to minimise $ab$ subject to the constraint $a^2k^2 + b^2h^2 = a^2b^2$. The usual way to solve problems of that sort is to use the method of Lagranga multipliers.
 
  • #3
Opalg said:
If I understand it correctly, the problem is to find an ellipse symmetric about the coordinate axes and passing through the fixed point $(h,k)$, such that the ellipse has the minimum possible area. (The question says maximum area, but in fact the only critical point is a minimum, and the maximum area is unbounded.)

The equation of the ellipse is $\dfrac{x^2}{a^2} + \dfrac{y^2}{b^2} = 1$, and we have to choose $a$ and $b$ so as to minimise the area of the ellipse, which is $\pi ab.$ The condition for the point $(h,k)$ to lie on the ellipse is $\dfrac{h^2}{a^2} + \dfrac{k^2}{b^2} = 1$, or $a^2k^2 + b^2h^2 = a^2b^2$. So we want to minimise $ab$ subject to the constraint $a^2k^2 + b^2h^2 = a^2b^2$. The usual way to solve problems of that sort is to use the method of Lagranga multipliers.

thanks sorry but the students here haven't studied 2wo variables yet so it should be answerred or with one variable or with parametrics So I wrote parametrics in what I did
can you or anyone help me ??
 
  • #4
Perhaps you could solve the constraint for either of the two variables and then use substitution to obtain an objective function in one variable...(Thinking)
 

FAQ: Maximizing Area of an Ellipse Passing Through a Fixed Point

1. What is an ellipse passing by a point?

An ellipse passing by a point is a geometric figure formed by the intersection of a cone and a plane that does not pass through the center of the cone. It is a closed curve that resembles a flattened circle.

2. How can you determine the equation of an ellipse passing by a point?

The equation of an ellipse passing by a point can be determined using the coordinates of the point and the center of the ellipse, as well as the length of the major and minor axes. The general equation is (x-h)^2/a^2 + (y-k)^2/b^2 = 1, where (h,k) is the center of the ellipse and a and b are the lengths of the major and minor axes, respectively.

3. What is the significance of an ellipse passing by a point in real life?

An ellipse passing by a point has many real-life applications, such as in astronomy for describing the orbits of planets around the sun, in engineering for designing curved structures, and in optics for describing the shape of lenses and mirrors.

4. How do you know if a point lies on an ellipse passing by a point?

To determine if a point lies on an ellipse passing by a point, you can substitute the coordinates of the point into the equation of the ellipse. If the equation holds true, then the point lies on the ellipse.

5. Can you have an ellipse passing by a point with a negative major axis?

Yes, it is possible to have an ellipse passing by a point with a negative major axis. This simply means that the ellipse is oriented in a different direction, but it still follows the same general equation (x-h)^2/a^2 + (y-k)^2/b^2 = 1.

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