Math Problem Statement

Suppose x^3 * y + 5 * x * y^5 = 3. Find dy/dx in terms of x and y.

Solution

To find dydx\frac{dy}{dx} for the equation given:

x3y+5xy5=3x^3 \cdot y + 5 \cdot x \cdot y^5 = 3

we'll use implicit differentiation with respect to xx.

Step-by-Step Solution

  1. Differentiate both sides with respect to xx: ddx(x3y+5xy5)=ddx(3)\frac{d}{dx}(x^3 \cdot y + 5 \cdot x \cdot y^5) = \frac{d}{dx}(3)

  2. Apply the product rule on each term of the left side. For the first term x3yx^3 \cdot y: ddx(x3y)=ddx(x3)y+x3dydx=3x2y+x3dydx\frac{d}{dx}(x^3 \cdot y) = \frac{d}{dx}(x^3) \cdot y + x^3 \cdot \frac{dy}{dx} = 3x^2 \cdot y + x^3 \cdot \frac{dy}{dx}

  3. Apply the product rule on the second term 5xy55 \cdot x \cdot y^5: ddx(5xy5)=5ddx(x)y5+5xddx(y5)\frac{d}{dx}(5 \cdot x \cdot y^5) = 5 \cdot \frac{d}{dx}(x) \cdot y^5 + 5 \cdot x \cdot \frac{d}{dx}(y^5)

    • Differentiate xx to get 11, so the first part is 5y55 \cdot y^5.
    • Differentiate y5y^5 to get 5y4dydx5y^4 \cdot \frac{dy}{dx}, so the second part is 5x5y4dydx=25xy4dydx5 \cdot x \cdot 5y^4 \cdot \frac{dy}{dx} = 25xy^4 \cdot \frac{dy}{dx}.

    Putting it together: ddx(5xy5)=5y5+25xy4dydx\frac{d}{dx}(5 \cdot x \cdot y^5) = 5y^5 + 25xy^4 \cdot \frac{dy}{dx}

  4. Substitute back into the equation: 3x2y+x3dydx+5y5+25xy4dydx=03x^2 \cdot y + x^3 \cdot \frac{dy}{dx} + 5y^5 + 25xy^4 \cdot \frac{dy}{dx} = 0

  5. Isolate dydx\frac{dy}{dx}: Combine all terms involving dydx\frac{dy}{dx}: x3dydx+25xy4dydx=3x2y5y5x^3 \cdot \frac{dy}{dx} + 25xy^4 \cdot \frac{dy}{dx} = -3x^2 \cdot y - 5y^5

  6. Factor out dydx\frac{dy}{dx}: dydx(x3+25xy4)=3x2y5y5\frac{dy}{dx} (x^3 + 25xy^4) = -3x^2 \cdot y - 5y^5

  7. Solve for dydx\frac{dy}{dx}: dydx=3x2y5y5x3+25xy4\frac{dy}{dx} = \frac{-3x^2 \cdot y - 5y^5}{x^3 + 25xy^4}

Final Answer

dydx=3x2y5y5x3+25xy4\frac{dy}{dx} = \frac{-3x^2 \cdot y - 5y^5}{x^3 + 25xy^4}

Would you like further details or have any questions on this?

Here are some related questions:

  1. How does implicit differentiation work in finding derivatives for non-explicit functions?
  2. What are some practical applications of implicit differentiation?
  3. How does the product rule apply to functions of two variables like xx and yy?
  4. What would happen if we wanted to find the second derivative, d2ydx2\frac{d^2y}{dx^2}?
  5. Why is it necessary to rearrange the equation to isolate dydx\frac{dy}{dx} in implicit differentiation?

Tip: When using implicit differentiation, remember to apply the product and chain rules carefully whenever yy is multiplied by functions of xx.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Implicit Differentiation
Product Rule
Differentiation

Formulas

d/dx (uv) = u'v + uv' (Product Rule)
Implicit differentiation of terms involving y with respect to x: d(y)/dx = dy/dx

Theorems

-

Suitable Grade Level

College Calculus