Answer :
Answer:
[tex]y'=\frac{-9x^2-2y}{2(x+4y)}[/tex]
General Formulas and Concepts:
Algebra
- Equality Properties
Calculus
- Chain Rule: [tex]\frac{d}{dx}[f(g(x))] =f'(g(x)) \cdot g'(x)[/tex]
- Basic Power Rule: f’(x) = c·nxⁿ⁻¹
- Derivative of a constant equals 0
- Implicit Differentiation
Step-by-step explanation:
Step 1: Define equation
3x³ + 2xy + 4y² = 0
Step 2: Find 1st Derivative
- Set up Derivative: [tex]\frac{dy}{dx} [3x^3 + 2xy + 4y^2 = 0][/tex]
- Take Implicit Differentiation: [tex]9x^2+(2y+2xy')+8yy'=0[/tex]
Step 3: Find Derivative (Solve for y')
- Define: [tex]9x^2+(2y+2xy')+8yy'=0[/tex]
- Move 9x² over: [tex]2y+2xy'+8yy'=-9x^2[/tex]
- Move 2y over: [tex]2xy'+8yy'=-9x^2-2y[/tex]
- Factor y': [tex]y'(2x+8y)=-9x^2-2y[/tex]
- Isolate y': [tex]y'=\frac{-9x^2-2y}{2x+8y}[/tex]
- Factor GCF: [tex]y'=\frac{-9x^2-2y}{2(x+4y)}[/tex]
Answer:
[tex]\frac{dy}{dx}= -\frac{9x^2+2y}{2(x+4y)}[/tex]
Step-by-step explanation:
Find the derivative of [tex]3x^3 + 2xy + 4y^2 = 0[/tex].
In order to find the derivative of this function, [tex]\frac{dy}{dx}[/tex], we can start by noticing that there are two variables in this problem, x and y.
Since we want the derivative with respect to x, every time we encounter the variable “y” in this problem we can change it to [tex]\frac{dy}{dx}[/tex]. We will see this happen later on in the solving process by using implicit differentiation.
Let’s start by taking the derivative of the entire function:
- [tex]\frac{d}{dx} (3x^3 + 2xy + 4y^2 = 0)[/tex]
Using the Power Rule and the Product Rule, we can perform implicit differentiation on this equation. Let’s take the derivative of each separate piece in this function:
[tex]3x^3 \rightarrow 3(3x^3^-^1) \rightarrow 9x^2[/tex] Power Rule
[tex]2xy \rightarrow (2x \times \frac{dy}{dx} + y \times 2)[/tex] Product Rule
[tex]4y^2 \rightarrow 2(4y) \times \frac{dy}{dx} \rightarrow 8y \times \frac{dy}{dx}[/tex] Power Rule & Implicit Differentiation
Let’s combine these steps into one comprehensive operation:
- [tex]9x^2 + (2x \times \frac{dy}{dx} + y \times 2) + 8y \times \frac{dy}{dx} = 0[/tex]
Simplify.
- [tex]9x^2 + 2x\frac{dy}{dx} + 2y + 8y \frac{dy}{dx} = 0[/tex]
Keep all terms containing [tex]\frac{dy}{dx}[/tex] on the left side of the equation and move everything else to the right side of the equation. This way we can solve for [tex]\frac{dy}{dx}[/tex], which, in this case, is the derivative of the original function.
Subtract [tex]9x^2[/tex] and [tex]2y[/tex] from both sides of the equation.
- [tex]2x\frac{dy}{dx} +8y \frac{dy}{dx} = -9x^2-2y[/tex]
Factor out dy/dx from the left side of the equation.
- [tex]\frac{dy}{dx}(2x+8y) = -9x^2-2y[/tex]
Divide both sides of the equation by (2x + 8y).
- [tex]\frac{dy}{dx}= \frac{-9x^2-2y}{2x+8y}[/tex]
You can leave it in this form, or you can convert this to either:
- [tex]\frac{dy}{dx}= \frac{-9x^2-2y}{2(x+4y)}[/tex]
- [tex]\frac{dy}{dx}= -\frac{9x^2+2y}{2(x+4y)}[/tex]