197k views
2 votes
Given the equation x² + 4y² = 16, what is the expression that represents the second derivative with respect to x, or d²/dx², of the function defined by this equation?"

1 Answer

4 votes

Final answer:

The second derivative of the function defined implicitly by the equation x² + 4y² = 16 involves implicit differentiation, the Chain Rule, and the Quotient Rule to obtain an expression for d²y/dx².

Step-by-step explanation:

Finding the Second Derivative

To find the second derivative of the function implicitly defined by the equation x² + 4y² = 16, we must first implicitly differentiate with respect to x to get the first derivative dy/dx and then differentiate again to obtain the second derivative d²y/dx².

Starting with the given equation:

x² + 4y² = 16

First differentiation with respect to x (using the Chain Rule for y since y is a function of x):

  1. 2x + 8y · (dy/dx) = 0.
  2. Solve for dy/dx: (dy/dx) = -2x/(8y) = -x/(4y).

Then, differentiate dy/dx with respect to x to get d²y/dx²:

  1. (d/dx) (-x/(4y)) = (d/dx) (-1/4 · x/y).
  2. Using the Quotient Rule, we have:
  3. d²y/dx² = (-1/4 · (y · (d/dx)(x) - x · (d/dx)(y))) / y².
  4. After substituting (dy/dx) = -x/(4y), simplify to find the second derivative.

The expression for the second derivative involves applying the differentiation rules dealing with implicit differentiation, using the Chain Rule and the Quotient Rule.

User Gautam Chibde
by
7.3k points