212k views
5 votes
Find {d y}{d x} if x(8ʸ )=4 x⁵ +3 y⁴ {d y}/{d x}=

User Joe Slater
by
8.5k points

2 Answers

2 votes
To find \(\frac{{dy}}{{dx}}\) when \(x \cdot 8^y = 4x^5 + 3y^4\), we'll use implicit differentiation.

Given the equation:
\[x \cdot 8^y = 4x^5 + 3y^4\]

Let's differentiate both sides of the equation with respect to \(x\):

For the left-hand side \(x \cdot 8^y\):
- Apply the product rule: \(x \cdot 8^y\)
- The derivative of \(x\) with respect to \(x\) is \(1\).
- The derivative of \(8^y\) with respect to \(x\) is \(8^y \cdot \ln(8) \cdot \frac{{dy}}{{dx}}\) using the chain rule.

For the right-hand side \(4x^5 + 3y^4\):
- Differentiate each term separately.
- The derivative of \(4x^5\) with respect to \(x\) is \(20x^4\) using the power rule.
- The derivative of \(3y^4\) with respect to \(x\) is \(12y^3 \cdot \frac{{dy}}{{dx}}\) using the chain rule.

Setting up the equation:
\[1 \cdot 8^y + x \cdot \ln(8) \cdot 8^y \cdot \frac{{dy}}{{dx}} = 20x^4 + 12y^3 \cdot \frac{{dy}}{{dx}}\]

Now, let's solve for \(\frac{{dy}}{{dx}}\):
\[8^y + x \cdot \ln(8) \cdot 8^y \cdot \frac{{dy}}{{dx}} = 20x^4 + 12y^3 \cdot \frac{{dy}}{{dx}}\]

Group the terms involving \(\frac{{dy}}{{dx}}\) on one side:
\[x \cdot \ln(8) \cdot 8^y \cdot \frac{{dy}}{{dx}} - 12y^3 \cdot \frac{{dy}}{{dx}} = 20x^4 - 8^y\]

Factor out \(\frac{{dy}}{{dx}}\):
\[\frac{{dy}}{{dx}} \cdot (x \cdot \ln(8) \cdot 8^y - 12y^3) = 20x^4 - 8^y\]

Finally, solve for \(\frac{{dy}}{{dx}}\):
\[\frac{{dy}}{{dx}} = \frac{{20x^4 - 8^y}}{{x \cdot \ln(8) \cdot 8^y - 12y^3}}\]

This expression gives the value of \(\frac{{dy}}{{dx}}\) in terms of the given variables \(x\) and \(y\).
User Erik Hinton
by
8.0k points
3 votes

Final answer:

The question requires finding the derivative of y with respect to x given an equation involving x and y. Implicit differentiation is used, applying the product rule and then differentiating each part separately. The exact derivative will depend on the method applied and additional context.

Step-by-step explanation:

The question asks to find the derivative of y with respect to x, given the equation x(8ⁿ) = 4x⁵ + 3y⁴. To solve this, we need to implicitly differentiate both sides of the equation with respect to x.

Let's differentiate the given function:

  1. First, apply the product rule to x times 8ⁿ, which gives us dx/dx · 8ⁿ + x · d/dx(8ⁿ).
  2. Then, differentiate the right side of the equation, which is straightforward.
  3. Finally, solve for {d y}/{d x} since the question asks for this derivative.

However, without more context or a specific method for differentiation, we can't provide an exact numerical answer.

User Odalet
by
8.4k points
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