Show that y can be written as a function of x

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In summary, using the Implicit Function Theorem, we can show that y can be written as a function of x near the point (x,y)=(0,0) with the given equation x3+y3=6x+2y. The partial derivative of y, Fy, is not equal to 0 at the point (0,0), allowing us to write y as a function of x using the formula y'(x)=(-Fx)/(Fy). At (0,0), Fy=-2 and y'(0,0)=-3, confirming that y can indeed be written as a function of x near the point (0,0).
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Homework Statement



Show that y can be written as a function of x near the point (x,y)=(0,0) with

x3+y3=6x+2y and what y'(x) is equal to.

Homework Equations



Implicit Function Theorem

The Attempt at a Solution



By the Implicit Function Theorem, if the partial derivative of y, Fy, does NOT equal 0 at a certain point then y can be

written as a function of x at that certain point.

First, I set the equation to x3+y3-6x-2y=0=F(x,y)

Then I use the formula:

y'(x)=(-Fx)/(Fy)

Thus y'(x)=(-3x2+6)/(3y2-2)

In other words, I am trying to show that the partial derivatives with respect to y

(Fy) does NOT equal zero.

At (0,0), Fy=3(0)2-2= -2

And at y'(0,0)=-3 I am not sure if I applied the Implicit Function Theorem correctly in this problem. Can

anyone see if I miss anything? Remember I ONLY have to show that that y can be

written as a function of x near the point (x,y)=(0,0), nothing less or more.
 
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This looks good.
 

1. How do you show that y can be written as a function of x?

To show that y can be written as a function of x, we need to demonstrate that there exists a relationship between y and x where for every input x, there is a unique output y. This can be done by using mathematical methods such as substitution, elimination, or graphing.

2. Why is it important to show that y can be written as a function of x?

Showing that y can be written as a function of x is important because it allows us to understand the relationship between two variables and make predictions about the behavior of the function. It also helps us to solve equations and model real-life situations.

3. Can y be written as a function of x if it is not explicitly given?

Yes, y can still be written as a function of x even if it is not explicitly given. In this case, we can use data points or information about the relationship between y and x to determine the form of the function. It may require some trial and error, but it is still possible to express y as a function of x.

4. How do you know if a relationship between y and x is a function?

A relationship between y and x is a function if for every input x, there is exactly one output y. This means that there cannot be multiple outputs for the same input. We can also use the vertical line test to determine if a graph represents a function. If a vertical line passes through more than one point on the graph, then it is not a function.

5. Are there any limitations to showing that y can be written as a function of x?

Yes, there are limitations to showing that y can be written as a function of x. For example, there may be cases where the relationship between y and x is not a function due to the presence of multiple outputs for the same input. In such cases, we can still use other methods to represent the relationship, such as using a piecewise function.

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