Implicit Differentiation

In summary: However, remember to be careful when substituting values into variables. In summary, the conversation discusses using implicit differentiation to find the equation of a tangent line to a curve at a given point. The person has trouble getting (dy/dx) alone and asks if they can plug in the coordinates to simplify the equation. The expert suggests doing so but cautions to be careful when substituting values into variables.
  • #1
Spiralshell
15
0

Homework Statement


Use implicit differentiation to find an equation of the tangent line to the curve at the given point.

x^2+y^2=(2x^2+2y^2-x)^2 @ (0,(1/2))

Homework Equations


The Attempt at a Solution



So, I don't have a problem differentiating this.

Which I get 2x+2y(dy/dx)=2(2x^2+2y^2-x)(4x+4y(dy/dx)-1)

I am having trouble getting (dy/dx) alone. I was wondering if I could plug in the coordinates and treat (dy/dx) like a variable (e.g. being added and subtracted to other dy/dx like 1(dy/dx)-2(dy/dx)=-1?)

So, could I just plug in (0,(1/2))? Also, I have a test tomorrow and I was wondering in your expert opinions (I know you don't know my professor), but do you think it would be possible that he wants me to simplify this on a test instead (I mean is that more shall I say proper)?

If that is the case when I have 2 large polynomials is it true that I can do something like:
using (2x^2+2y^2-x)(4x+4y(dy/dx)-1) take out 4y(dy/dx) and multiply it by the other polynomial? by that I mean

(2x^2+2y^2-x)(4x+4y(dy/dx)-1) becomes (2x^2+2y^2-x)(4x-1)+4y(dy/dx)(2x^2+2y^2-x)

or like (2x^2+2y^2-x)(4x+4y(dy/dx)-1) is equivalent to (2x^2+2y^2)((4x+4y(dy/dx)-1)-x(4x+4y(dy/dx)-1)?
 
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  • #2
Spiralshell said:

Homework Statement


Use implicit differentiation to find an equation of the tangent line to the curve at the given point.

x^2+y^2=(2x^2+2y^2-x)^2 @ (0,(1/2))

Homework Equations





The Attempt at a Solution



So, I don't have a problem differentiating this.

Which I get 2x+2y(dy/dx)=2(2x^2+2y^2-x)(4x+4y(dy/dx)-1)

I am having trouble getting (dy/dx) alone.
You should probably bone up on your algebra skills then, eh?
I was wondering if I could plug in the coordinates and treat (dy/dx) like a variable (e.g. being added and subtracted to other dy/dx like 1(dy/dx)-2(dy/dx)=-1?)

So, could I just plug in (0,(1/2))?
Yes, that is a very good idea to simplify it quickly, especially when time is at a premium.
 

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 one variable. In other words, it is a way to find the rate of change of a function that is written in terms of multiple variables.

2. Why is implicit differentiation useful?

Implicit differentiation allows us to find the derivative of a function without having to solve for one variable in terms of the other. This is especially helpful when dealing with complex equations that cannot be easily solved for one variable.

3. How is implicit differentiation different from explicit differentiation?

Explicit differentiation is used to find the derivative of a function that is explicitly written in terms of one variable. In implicit differentiation, the function is not explicitly written in terms of one variable, so we use the chain rule and other techniques to find the derivative.

4. What are the steps to perform implicit differentiation?

The steps to perform implicit differentiation are as follows:
1. Take the derivative of both sides of the equation with respect to the variable you are trying to find the derivative of.
2. Use the chain rule to differentiate any terms with multiple functions.
3. Simplify the resulting equation and solve for the derivative.

5. What are some common applications of implicit differentiation?

Implicit differentiation has many practical applications in fields such as physics, engineering, economics, and more. It can be used to find rates of change, slopes of curves, and optimization problems. It is also useful in finding solutions to differential equations that cannot be solved explicitly.

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