111k views
2 votes
The sum of two non-negative numbers (x) and (y) is 24. Determine the values of (x) and (y) that minimize the value of (x^2 - 2y^2).

User Misterbear
by
7.8k points

1 Answer

3 votes

Final answer:

To minimize the expression x^2 - 2y^2 given that x + y = 24, you express y in terms of x, substitute it into the original expression, and then use differentiation to find the critical point that will give the minimum value, ensuring x and y are non-negative.

Step-by-step explanation:

To find the values of x and y that minimize the expression x2 - 2y2 given that x + y = 24 and both are non-negative numbers, we can use calculus or reason through the symmetry of the equation. Since we're dealing with a minimization problem of a quadratic expression, and we have a linear constraint, this is a perfect candidate for the method of Lagrange multipliers or completing the square. However, for a high school level approach, we can make do with a simpler method.

First, express y in terms of x using the equation y = 24 - x. Then, substitute for y in the original expression to get a quadratic equation in terms of x only. Now, we simplify the equation: x2 - 2(24 - x)2.

Upon expanding the squared term and simplifying, we can differentiate the resulting expression with respect to x to find the critical points and then test these points to find the minimum value. Alternatively, since the second derivative will be positive (a cup-upward parabola), the critical point will give us the minimum value of the quadratic function.

Remember to check that the values of x and y are non-negative, as per the constraints of the problem. The final step would be to find the corresponding value of y once the minimizing value of x is determ

User NereuJunior
by
8.3k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories