Chapter 3: Problem 19
Differentiate implicily to find \(d y / d x\). $$ \sqrt{x}+\sqrt{y}=1 $$
Short Answer
Expert verified
\( \frac{dy}{dx} = - \frac{\sqrt{y}}{\sqrt{x}} \)
Step by step solution
01
Differentiate Both Sides with Respect to x
Differentiate each term on both sides separately. Remember that y is a function of x.
02
Differentiate the First Term
The first term is \( \sqrt{x} \). Applying the chain rule, the derivative of \( \sqrt{x} \) with respect to \( x \) is \( \frac{1}{2\sqrt{x}} \).
03
Differentiate the Second Term
The second term is \( \sqrt{y} \). Using the chain rule, its derivative with respect to \( x \) is \( \frac{1}{2\sqrt{y}} \cdot \frac{dy}{dx} \).
04
Differentiate the Right Side
The right side of the equation is simply 1. The derivative of a constant is 0.
05
Combine the Results
Combine the derivatives obtained: \( \frac{1}{2\sqrt{x}} + \frac{1}{2\sqrt{y}} \cdot \frac{dy}{dx} = 0 \).
06
Solve for \( \frac{dy}{dx} \)
Isolate \( \frac{dy}{dx} \) by solving the resulting equation: \[ \frac{dy}{dx} = - \frac{\sqrt{y}}{\sqrt{x}} \]
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Chain Rule in Implicit Differentiation
When differentiating implicitly, the chain rule is a crucial tool. This is because we recognize that some variables, like y in our example, depend on another variable, x. For instance, when differentiating \( \sqrt{y} \ \) with respect to x, we first treat \( y \ \) as a function of x. We then apply the chain rule:
- Differentiate the outer function: \( \sqrt{y} \ \), which gives \( \frac{1}{2 \sqrt{y}} \ \)
- Differentiate the inner function (y) with respect to x: \( \frac{dy}{dx} \ \)
- Combine both results: \( \frac{1}{2 \sqrt{y}} \cdot \frac{dy}{dx} \ \)
Understanding Derivatives
Derivatives measure how a function changes as its input changes. In implicit differentiation, you need to find the rate at which y changes with respect to x. In our problem \( \sqrt{x} + \sqrt{y} = 1 \ \), differentiating each term separately ensures precision.
- For \( \sqrt{x} \ \), the standard derivative is \( \frac{1}{2 \sqrt{x}} \ \)
- For \( \sqrt{y} \ \), we again use the chain rule to get \( \frac{1}{2 \sqrt{y}} \cdot \frac{dy}{dx} \ \)
- Constants like 1 differentiate to 0
Functions of x and their Relationships
Functions describe the relationship between variables. In our exercise, \( x \ \) and \( y \ \) are related by \( \sqrt{x} + \sqrt{y} = 1 \ \). This means any change in \( x \ \) affects \( y \ \). Recognizing this relationship is key in implicit differentiation.
- When x changes, we need to adjust y, maintaining the equation balance
- This relationship guides us in applying the chain rule correctly
- Ensuring we differentiate each term with respect to x