Piecewise Function: Finding Constants for Continuity

In summary, the conversation is about a piecewise function with unknown constants that needs to be made continuous. The function has different expressions for different intervals of x and the goal is to find values for a, b, c and d that will make the function continuous on the entire domain. The speaker believes that c and d should both be -2 for continuity, but is unsure about the values of a and b.
  • #1
lomantak
10
0
Hello,

Here is a piecewise function that I came over, and it does not seem to have a definite answer, and so I beg of your recondite knowledge to guide me on this one:f(x) =
ax^2 + bx + c if -oo < x < 0
d if x = 0
[(x^2)(sin(1/x))]-2 if 0 < x < oo

Find all values of the constants a, b, c and d that make the function f continuous on -oo < x < oo.

I think a, b and c are all reals, and d is -2, but I am not sure...
 
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  • #2
For continuity you need c=d=-2. a and b could be anything.
 
  • #3


Hello,

Thank you for sharing this piecewise function with us. Finding the constants for continuity in a piecewise function can be a bit challenging, but with the right approach, we can find the correct values for a, b, c, and d.

First, let's define what it means for a function to be continuous. A function is continuous if it has no gaps or breaks in its graph. In other words, the function's value at a certain point should be equal to the limit of the function as it approaches that point from both sides.

Now, let's look at the function f(x) that you have provided. We need to find the values of a, b, c, and d that will make this function continuous on the interval -oo < x < oo. To do this, we need to consider the following cases:

Case 1: x < 0
In this case, the function is equal to ax^2 + bx + c. For the function to be continuous, the value of this expression at x = 0 should be equal to the limit of the function as x approaches 0 from the left. This means that we need to have:

ax^2 + bx + c = lim (x->0-) f(x)
ax^2 + bx + c = lim (x->0-) [(x^2)(sin(1/x))]-2
ax^2 + bx + c = 0 - 2 = -2

Case 2: x > 0
In this case, the function is equal to [(x^2)(sin(1/x))]-2. Similarly, for the function to be continuous, the value of this expression at x = 0 should be equal to the limit of the function as x approaches 0 from the right. This means that we need to have:

[(x^2)(sin(1/x))]-2 = lim (x->0+) f(x)
[(x^2)(sin(1/x))]-2 = lim (x->0+) [(x^2)(sin(1/x))]-2
[(x^2)(sin(1/x))]-2 = -2

Since we have the same value for both cases, we can conclude that d = -2. Now, let's consider the first case again and substitute d = -2:

ax^2 + bx + c = lim (x->0-) f(x)
ax
 

1. What is a piecewise function?

A piecewise function is a mathematical function that is defined by different formulas or rules for different intervals or "pieces" of the function's domain.

2. How do you find the constants for continuity in a piecewise function?

To find the constants for continuity in a piecewise function, you need to set the different pieces of the function equal to each other at the points where they meet. Then, solve for the constants using algebraic manipulation.

3. What is the importance of finding constants for continuity in a piecewise function?

Finding the constants for continuity in a piecewise function is important because it ensures that the function is continuous at the points where the different pieces meet. This means that the function has no abrupt jumps or breaks, and can be graphed smoothly.

4. Can a piecewise function have more than two pieces?

Yes, a piecewise function can have any number of pieces, depending on the complexity of the function's domain and the number of conditions needed to define the function at different intervals.

5. How do you graph a piecewise function?

To graph a piecewise function, plot the points where the different pieces of the function meet and then connect these points with lines or curves, depending on the shape of the function. Make sure to include open or closed circles at the endpoints of the pieces to indicate whether the function is defined at those points or not.

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