Answer:
4.5
Step-by-step explanation:
Use the distance formula to get sqrt(2^2+4^2) or sqrt20, which is 2sqrt5. sqrt5 is approximately 2.236, so 2*2.236 is 4.472 or 4.5.
Wow, Lagrange multipliers in high school!
As a rule with these Lagrange multiplier problems, when the problem is symmetrical with respect to interchange of the variables, the solution almost always ends up with all the variables equal -- what else could it be?
We want to maximize the area of a rectangle with sides x and y subject to the perimeter being constant.
(i)
The area of a rectangle is just the product of its sides:
A = f(x,y) = xy
(ii)
The perimeter of a rectangle is the sum of its sides:
P = g(x,y) = x + x + y + y = 2x+2y
(iii)
Usually I like to form the objective function E=f-λg before I take the derivatives. I usually use a lambda not a gamma for the multiplier.
Let's do what they ask. They want the gradient ∇f(x, y)
∇f(x, y) = (y, x)
(iv)
λ∇g(x, y) = (2λ, 2λ)
(v)
I'm not sure what γ=1/2y is about; I'll solve it like I know how and see where we are.
There it is. We get
y = 2λ
so we also find
x = 2λ
(vi)
We have y=x=2λ so we've shown the variables are equal, i.e. our rectangle is a square. We can solve for λ using our constraint:
P = 2x+2y = 8λ
λ=P/8
so as expected we have a square with side length P/4:
x=y=2λ=P/4
Answer:
It's a isosceles triangle........
I hope this is right....
Answer:
x =-7. .y=6
Step-by-step explanation:
3x + 2y = -9
(X – Y = -13)×3
3x + 2y = -9
3x – 3y = -39
5y = 30
y=6
3x +2(6)=-9
3x=-21
x=-7