Implicit Differentiation Question - Stuck

In summary, the conversation discusses using implicit differentiation to find y' given y/(x-y) = x^2+1. The writer shows their attempt at solving the problem and asks for help with the next step. The expert advises to solve for y and then differentiate the resulting expression to reach the correct answer.
  • #1
playdohh
5
0

Homework Statement



Use implicit differentiation to find y' given y/(x-y) = x^2+1.

Homework Equations


The Attempt at a Solution



Hi, I'm doing an online course for Calculus 12, and I have been struggling with Implicit Differentiation. I am hoping someone could maybe help me. Thanks.

I'm not positive I'm doing this right, but maybe someone can point me in the right direction. This is what I have so far

y/(x-y) = x^2+1

y=(x^2+1)(x-y)

y' = (2x)(x-y)+(x^2+1)(1-y')

y' = 2x^2-2xy+x^2-x^2y'+1-y'

This is where I get stuck and am not sure if I'm making a mistake or know what to do next. Any help would be appreciated, thank you.
 
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  • #2
y/(x-y) = x^2+1

y=(x^2+1)(x-y)

y' = (2x)(x-y)+(x^2+1)(1-y')

y' = 2x^2-2xy+x^2-x^2y'+1-y'

2y'+x^2y' = 3x^2-2xy+1

y'(2+x^2) = 3x^2-2xy+1

y' = (3x^2-2xy+1)/(2+x^2)

That's what I got as my continued attempt, does that look right?
 
  • #3
playdohh said:
y/(x-y) = x^2+1

y=(x^2+1)(x-y)

y' = (2x)(x-y)+(x^2+1)(1-y')
Up to here is correct. If you did the subsequent algebra correctly, you should have the right answer.

y' = 2x^2-2xy+x^2-x^2y'+1-y'

2y'+x^2y' = 3x^2-2xy+1

y'(2+x^2) = 3x^2-2xy+1

y' = (3x^2-2xy+1)/(2+x^2)

That's what I got as my continued attempt, does that look right?
In this problem, you can solve the original equation for y. Try that and then differentiate the resulting expression. See if you get the same result.
 

Related to Implicit Differentiation Question - Stuck

1. What is implicit differentiation?

Implicit differentiation is a mathematical technique used to find the derivative of a function that is not explicitly written in terms of the independent variable. It is typically used when the dependent variable cannot be easily isolated and solved for.

2. When is implicit differentiation used?

Implicit differentiation is used in situations where the dependent variable is not explicitly written in terms of the independent variable. It is commonly used in curve sketching, optimization problems, and related rates.

3. How does implicit differentiation differ from explicit differentiation?

Explicit differentiation is used to find the derivative of a function that is written explicitly in terms of the independent variable. Implicit differentiation, on the other hand, is used to find the derivative of a function that is not explicitly written in terms of the independent variable.

4. What are the steps for implicit differentiation?

The steps for implicit differentiation are as follows:
1. Differentiate both sides of the equation with respect to the independent variable.
2. Use the chain rule to differentiate any terms with nested functions.
3. Isolate the derivative of the dependent variable on one side of the equation.
4. Solve for the derivative by simplifying the equation.

5. What are some common mistakes made in implicit differentiation?

Some common mistakes made in implicit differentiation include:
- Forgetting to use the chain rule when differentiating nested functions.
- Incorrectly distributing the derivative to terms that do not have the independent variable.
- Forgetting to differentiate constants as 0.
- Not isolating the derivative of the dependent variable on one side of the equation.
- Making algebraic errors when solving for the derivative.

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