Mathematics Exam  >  Mathematics Questions  >  The maximum value of f(x,y) =x2 + 2y2 subject... Start Learning for Free
The maximum value of f(x,y) = x2 + 2y2 subject to the constraint  y - x2 + 1 = 0 is  ___________
    Correct answer is '1'. Can you explain this answer?
    Most Upvoted Answer
    The maximum value of f(x,y) =x2 + 2y2 subject to the constraint y - x2...
    Solution:

    The given function is f(x, y) = x^2 - 2y^2.

    1. Find the gradient of the constraint equation:
    The constraint equation is y - x^2 - 1 = 0. Taking the partial derivatives with respect to x and y, we get:
    ∂(y - x^2 - 1)/∂x = -2x
    ∂(y - x^2 - 1)/∂y = 1

    2. Set up the Lagrangian function:
    The Lagrangian function is given by L(x, y, λ) = f(x, y) + λ(g(x, y)), where g(x, y) is the constraint equation. In this case, g(x, y) = y - x^2 - 1. Thus, the Lagrangian function is:
    L(x, y, λ) = x^2 - 2y^2 + λ(y - x^2 - 1)

    3. Find the critical points:
    To find the critical points, we need to solve the following system of equations:
    ∂L/∂x = 0
    ∂L/∂y = 0
    g(x, y) = 0

    Taking the partial derivatives of L(x, y, λ) with respect to x, y, and λ, we get:
    ∂L/∂x = 2x - 2λx = 0
    ∂L/∂y = -4y + λ = 0
    g(x, y) = y - x^2 - 1 = 0

    From the first equation, we can solve for λ in terms of x:
    2x - 2λx = 0
    2 - 2λ = 0
    λ = 1

    Substituting λ = 1 into the second equation, we get:
    -4y + 1 = 0
    y = 1/4

    Substituting λ = 1 and y = 1/4 into the third equation, we get:
    1/4 - x^2 - 1 = 0
    x^2 = -3/4
    This equation has no real solutions for x.

    4. Determine the maximum value:
    Since x does not have any real solutions, there are no critical points. Therefore, we cannot apply the Lagrange Multiplier method to find the maximum value of f(x, y) subject to the constraint.

    However, we can observe that the given function f(x, y) = x^2 - 2y^2 is a quadratic function with a positive coefficient for the x^2 term. This means that the function opens upwards and has a minimum value, not a maximum value. Therefore, the statement that the maximum value of f(x, y) is 1 is incorrect.

    In conclusion, the correct answer cannot be determined as the Lagrange Multiplier method cannot be applied to find the maximum value, and the given function does not have a maximum value.
    Free Test
    Community Answer
    The maximum value of f(x,y) =x2 + 2y2 subject to the constraint y - x2...
    Consider x=0 y= -1 then constraint is satisfied and value is 2.
    Explore Courses for Mathematics exam
    Question Description
    The maximum value of f(x,y) =x2 + 2y2 subject to the constraint y - x2+ 1 = 0 is ___________Correct answer is '1'. Can you explain this answer? for Mathematics 2025 is part of Mathematics preparation. The Question and answers have been prepared according to the Mathematics exam syllabus. Information about The maximum value of f(x,y) =x2 + 2y2 subject to the constraint y - x2+ 1 = 0 is ___________Correct answer is '1'. Can you explain this answer? covers all topics & solutions for Mathematics 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for The maximum value of f(x,y) =x2 + 2y2 subject to the constraint y - x2+ 1 = 0 is ___________Correct answer is '1'. Can you explain this answer?.
    Solutions for The maximum value of f(x,y) =x2 + 2y2 subject to the constraint y - x2+ 1 = 0 is ___________Correct answer is '1'. Can you explain this answer? in English & in Hindi are available as part of our courses for Mathematics. Download more important topics, notes, lectures and mock test series for Mathematics Exam by signing up for free.
    Here you can find the meaning of The maximum value of f(x,y) =x2 + 2y2 subject to the constraint y - x2+ 1 = 0 is ___________Correct answer is '1'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of The maximum value of f(x,y) =x2 + 2y2 subject to the constraint y - x2+ 1 = 0 is ___________Correct answer is '1'. Can you explain this answer?, a detailed solution for The maximum value of f(x,y) =x2 + 2y2 subject to the constraint y - x2+ 1 = 0 is ___________Correct answer is '1'. Can you explain this answer? has been provided alongside types of The maximum value of f(x,y) =x2 + 2y2 subject to the constraint y - x2+ 1 = 0 is ___________Correct answer is '1'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice The maximum value of f(x,y) =x2 + 2y2 subject to the constraint y - x2+ 1 = 0 is ___________Correct answer is '1'. Can you explain this answer? tests, examples and also practice Mathematics tests.
    Explore Courses for Mathematics exam

    Top Courses for Mathematics

    Explore Courses
    Signup for Free!
    Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
    10M+ students study on EduRev