Math Problem Statement

Determine whether each equation defines y as a function of x If the equation does define y as a function of x, enter y in terms of x in the box provided. If the equation does not define y as a function of x, enter none in the box provided. 7x ^ 2 + 8y ^ 2 = 6 y none 29x ^ 2 + 5y = 2; y = Box Sigma Σ

Solution

Let's carefully determine whether each equation defines yy as a function of xx and find yy in terms of xx when possible.

Equation 1: 7x2+8y2=6y7x^2 + 8y^2 = 6y

To determine if yy is a function of xx, we need to check if for every xx, there is exactly one corresponding value of yy.

  1. Rewrite the equation to focus on yy: 8y26y+7x2=08y^2 - 6y + 7x^2 = 0

  2. This is a quadratic equation in terms of yy. A quadratic equation can have 0, 1, or 2 solutions for yy depending on the value of the discriminant. The quadratic equation can be written in the standard form: ay2+by+c=0ay^2 + by + c = 0 where a=8a = 8, b=6b = -6, and c=7x2c = 7x^2.

  3. Compute the discriminant Δ\Delta: Δ=b24ac=(6)2487x2=36224x2\Delta = b^2 - 4ac = (-6)^2 - 4 \cdot 8 \cdot 7x^2 = 36 - 224x^2

  4. Since the discriminant 36224x236 - 224x^2 can be positive, zero, or negative depending on the value of xx, the equation can have two different solutions, one solution, or no real solution for yy.

Because there can be more than one yy value for a given xx, Equation 1 does not define yy as a function of xx.

Answer for Equation 1: none

Equation 2: 29x2+5y=229x^2 + 5y = 2

Let's solve for yy to check if it is a function of xx.

  1. Rewrite the equation: 5y=229x25y = 2 - 29x^2

  2. Solve for yy: y=229x25y = \frac{2 - 29x^2}{5}

This is a linear equation, and for each xx, there is exactly one value of yy. Thus, Equation 2 defines yy as a function of xx.

Answer for Equation 2: y=229x25y = \frac{2 - 29x^2}{5}

Conclusion:

  1. Equation 1: 7x2+8y2=6y7x^2 + 8y^2 = 6y
    Answer: none (does not define yy as a function of xx).

  2. Equation 2: 29x2+5y=229x^2 + 5y = 2
    Answer: y=229x25y = \frac{2 - 29x^2}{5} (defines yy as a function of xx).

Would you like more details or have any questions?

Related Questions:

  1. How does the discriminant determine the number of solutions for a quadratic equation?
  2. What are some examples of equations that do not define functions?
  3. How can you graphically check if an equation defines a function?
  4. What is the significance of rewriting equations to solve for yy?
  5. How can linear equations always define functions?

Tip: Quadratic equations in yy can have up to two different solutions for each xx, so they often do not define yy as a function of xx.

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Math Problem Analysis

Mathematical Concepts

Functions
Quadratic Equations
Linear Equations

Formulas

Quadratic equation discriminant
Linear equation solution

Theorems

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Suitable Grade Level

High School