Implicit differentiation question

In summary, the conversation discusses a problem involving implicit differentiation and finding the correct answer at the point (3,1). Different approaches and answers are shared, with one involving basic arithmetic and the other using implicit differentiation to find the solution.
  • #1
rcurrie
1
0
Help! Keep running this and getting different answers, and none are right.

2xy^8 + 7xy = 27 at the point (3,1)
 
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  • #2
rcurrie said:
Help! Keep running this and getting different answers, and none are right.

2xy^8 + 7xy = 27 at the point (3,1)
Can you post the different answers with the respected work?

Thanks
Cbarker1
 
  • #3
rcurrie said:
Help! Keep running this and getting different answers, and none are right.

2xy^8 + 7xy = 27 at the point (3,1)
Answers to what question? There is no question or problem here!

IF the problem is "show that (3,1) satifies 2xy^8+ 7xy= 27" or "show that (3, 1) lies on the graph of 2xy^8+ 7xy= 27" then it is basic integer arithmetic.

2(3)(1)^8= 2(3)= 6.
7(3)(1)= 7(3)= 21.

What is the sum of 6 and 21?
 
  • #4
rcurrie said:
Help! Keep running this and getting different answers, and none are right.

2xy^8 + 7xy = 27 at the point (3,1)
The thread title mentions implicit differentiation. So, differentiate implicitly: $$2y^8 + 16xy^7y' + 7y + 7xy' = 0.$$ At the point $(3,1)$ that becomes $2 + 48y' + 7 + 21y' = 0$. so $69y' + 9 = 0$. That gives $y' = -\dfrac3{23}$. Is that the answer you are looking for?
 

1. What is implicit differentiation?

Implicit differentiation is a method used in calculus to find the derivative of a function that is not explicitly expressed in terms of its independent variable. It is commonly used when a function is given in the form of an equation rather than a specific formula.

2. How is implicit differentiation different from explicit differentiation?

Explicit differentiation is used to find the derivative of a function that is expressed explicitly in terms of its independent variable. Implicit differentiation, on the other hand, is used when the function is given in the form of an equation and cannot be easily solved for the dependent variable.

3. When should I use implicit differentiation?

Implicit differentiation is typically used when the function is not easily solvable for the dependent variable, or when the function contains both the dependent and independent variables in different forms (e.g. x and y). It is also useful when finding the derivative of inverse functions.

4. What are the steps for performing 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 for any terms containing the dependent variable.3. Solve for the derivative of the dependent variable.

5. Can implicit differentiation be used to find higher order derivatives?

Yes, implicit differentiation can be used to find higher order derivatives. The process is the same as finding the first derivative, but it may require multiple applications of the chain rule and product rule. It is also important to remember to use the notation for higher order derivatives (e.g. y'', y''', etc.) when solving for them.

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