Problem

Find dy/dx y^2=3x

The problem presented here involves calculus, specifically differentiation. The question is asking you to find the derivative of y with respect to x, denoted as dy/dx, for the given equation y^2 = 3x. This entails applying the rules of differentiation to both sides of the equation with respect to x, to solve for dy/dx. This would typically involve using implicit differentiation, since y is raised to a power and is not isolated. Implicit differentiation is used when dealing with equations where y and x are not easily separable.

$y^{2} = 3 x$

Answer

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Solution:

Step 1:

Apply differentiation to both sides of the equation with respect to $x$: $\frac{d}{dx}(y^2) = \frac{d}{dx}(3x)$.

Step 2:

Differentiate the left-hand side using the chain rule.

Step 2.1:

Invoke the chain rule for differentiation: $\frac{d}{dx}(f(g(x))) = f'(g(x)) \cdot g'(x)$, where $f(x) = x^2$ and $g(x) = y$.

Step 2.1.1:

Set $u = y$ to facilitate the application of the chain rule: $\frac{d}{du}(u^2) \cdot \frac{dy}{dx}$.

Step 2.1.2:

Apply the power rule for differentiation, which states $\frac{d}{du}(u^n) = n \cdot u^{n-1}$ for $n = 2$: $2u \cdot \frac{dy}{dx}$.

Step 2.1.3:

Substitute $y$ back in for $u$: $2y \cdot \frac{dy}{dx}$.

Step 2.2:

Express $\frac{dy}{dx}$ as $y'$: $2y \cdot y'$.

Step 3:

Differentiate the right-hand side of the equation.

Step 3.1:

Recognize that $3$ is a constant and differentiate $3x$ with respect to $x$: $3 \cdot \frac{d}{dx}(x)$.

Step 3.2:

Apply the power rule to $x$, where $n = 1$: $3 \cdot 1$.

Step 3.3:

Multiply $3$ by $1$ to get $3$.

Step 4:

Combine the differentiated left and right sides: $2y \cdot y' = 3$.

Step 5:

Isolate $y'$ by dividing both sides of the equation by $2y$.

Step 5.1:

Divide both sides by $2y$: $\frac{2y \cdot y'}{2y} = \frac{3}{2y}$.

Step 5.2:

Simplify the left-hand side.

Step 5.2.1:

Eliminate the common factor of $2$.

Step 5.2.1.1:

Cancel out the $2$s: $\frac{\cancel{2}y \cdot y'}{\cancel{2}y} = \frac{3}{2y}$.

Step 5.2.1.2:

Rewrite the simplified expression: $\frac{y \cdot y'}{y} = \frac{3}{2y}$.

Step 5.2.2:

Eliminate the common factor of $y$.

Step 5.2.2.1:

Cancel out the $y$s: $\frac{\cancel{y} \cdot y'}{\cancel{y}} = \frac{3}{2y}$.

Step 5.2.2.2:

Simplify to find $y'$: $y' = \frac{3}{2y}$.

Step 6:

Substitute $y'$ with $\frac{dy}{dx}$: $\frac{dy}{dx} = \frac{3}{2y}$.

Knowledge Notes:

The problem involves finding the derivative of $y$ with respect to $x$ given the equation $y^2 = 3x$. The solution employs several fundamental concepts of calculus:

  1. Differentiation: The process of finding the derivative, which represents the rate at which a function is changing at any given point.

  2. Chain Rule: A rule for differentiating compositions of functions. It states that the derivative of $f(g(x))$ is $f'(g(x)) \cdot g'(x)$.

  3. Power Rule: A basic rule of differentiation that states if $f(x) = x^n$, then $f'(x) = n \cdot x^{n-1}$.

  4. Constants in Differentiation: Constants are differentiated to zero. When differentiating a constant multiplied by a function, the constant remains and the function is differentiated.

  5. Simplifying Expressions: After differentiating, it is often necessary to simplify the expression to isolate the derivative ($\frac{dy}{dx}$ or $y'$).

In this problem, the chain rule is used to differentiate $y^2$ because $y$ is a function of $x$. The power rule is applied to both $y^2$ and $3x$. After differentiation, algebraic manipulation is used to solve for $\frac{dy}{dx}$.

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