Which Statement Best Describes How To Determine Whether $f(x)=x^4-x^3$ Is An Even Function?A. Determine Whether $(-x)^4 - (-x)^3$ Is Equivalent To $x^4 - X^3$.B. Determine Whether $\left(-x^4\right) -

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Understanding Even Functions

In mathematics, an even function is a function where f(βˆ’x)=f(x)f(-x) = f(x) for all x in the domain of the function. This means that if we replace x with -x in the function, the function remains unchanged. Even functions have symmetry about the y-axis and are often represented by functions with even powers of x.

Determining Even Functions: A Step-by-Step Guide

To determine whether a function is even, we need to check if f(βˆ’x)=f(x)f(-x) = f(x). Let's consider the given function f(x)=x4βˆ’x3f(x) = x^4 - x^3. To determine whether this function is even, we need to evaluate f(βˆ’x)f(-x) and compare it with f(x)f(x).

Option A: Evaluating (βˆ’x)4βˆ’(βˆ’x)3(-x)^4 - (-x)^3

One way to determine whether f(x)=x4βˆ’x3f(x) = x^4 - x^3 is an even function is to evaluate (βˆ’x)4βˆ’(βˆ’x)3(-x)^4 - (-x)^3 and compare it with x4βˆ’x3x^4 - x^3. Let's start by expanding (βˆ’x)4(-x)^4 and (βˆ’x)3(-x)^3.

(βˆ’x)4=(βˆ’x)(βˆ’x)(βˆ’x)(βˆ’x)=x4(-x)^4 = (-x)(-x)(-x)(-x) = x^4

(βˆ’x)3=(βˆ’x)(βˆ’x)(βˆ’x)(βˆ’x)=βˆ’x3(-x)^3 = (-x)(-x)(-x)(-x) = -x^3

Now, let's substitute these values into the expression (βˆ’x)4βˆ’(βˆ’x)3(-x)^4 - (-x)^3.

(βˆ’x)4βˆ’(βˆ’x)3=x4βˆ’(βˆ’x3)(-x)^4 - (-x)^3 = x^4 - (-x^3)

(βˆ’x)4βˆ’(βˆ’x)3=x4+x3(-x)^4 - (-x)^3 = x^4 + x^3

As we can see, (βˆ’x)4βˆ’(βˆ’x)3(-x)^4 - (-x)^3 is not equivalent to x4βˆ’x3x^4 - x^3. Therefore, option A is not the correct way to determine whether f(x)=x4βˆ’x3f(x) = x^4 - x^3 is an even function.

Option B: Evaluating (βˆ’x4)βˆ’(βˆ’x3)\left(-x^4\right) - \left(-x^3\right)

Another way to determine whether f(x)=x4βˆ’x3f(x) = x^4 - x^3 is an even function is to evaluate (βˆ’x4)βˆ’(βˆ’x3)\left(-x^4\right) - \left(-x^3\right) and compare it with x4βˆ’x3x^4 - x^3. Let's start by expanding (βˆ’x4)\left(-x^4\right) and (βˆ’x3)\left(-x^3\right).

(βˆ’x4)=βˆ’x4\left(-x^4\right) = -x^4

(βˆ’x3)=βˆ’x3\left(-x^3\right) = -x^3

Now, let's substitute these values into the expression (βˆ’x4)βˆ’(βˆ’x3)\left(-x^4\right) - \left(-x^3\right).

(βˆ’x4)βˆ’(βˆ’x3)=βˆ’x4+x3\left(-x^4\right) - \left(-x^3\right) = -x^4 + x^3

As we can see, (βˆ’x4)βˆ’(βˆ’x3)\left(-x^4\right) - \left(-x^3\right) is not equivalent to x4βˆ’x3x^4 - x^3. Therefore, option B is not the correct way to determine whether f(x)=x4βˆ’x3f(x) = x^4 - x^3 is an even function.

Option C: Evaluating f(βˆ’x)f(-x)

To determine whether f(x)=x4βˆ’x3f(x) = x^4 - x^3 is an even function, we need to evaluate f(βˆ’x)f(-x) and compare it with f(x)f(x). Let's start by substituting βˆ’x-x into the function.

f(βˆ’x)=(βˆ’x)4βˆ’(βˆ’x)3f(-x) = (-x)^4 - (-x)^3

f(βˆ’x)=x4βˆ’(βˆ’x3)f(-x) = x^4 - (-x^3)

f(βˆ’x)=x4+x3f(-x) = x^4 + x^3

As we can see, f(βˆ’x)f(-x) is not equivalent to f(x)f(x). Therefore, the function f(x)=x4βˆ’x3f(x) = x^4 - x^3 is not an even function.

Conclusion

In conclusion, to determine whether a function is even, we need to evaluate f(βˆ’x)f(-x) and compare it with f(x)f(x). The correct way to determine whether f(x)=x4βˆ’x3f(x) = x^4 - x^3 is an even function is to evaluate f(βˆ’x)f(-x) and compare it with f(x)f(x). The function f(x)=x4βˆ’x3f(x) = x^4 - x^3 is not an even function.

Key Takeaways

  • An even function is a function where f(βˆ’x)=f(x)f(-x) = f(x) for all x in the domain of the function.
  • To determine whether a function is even, we need to evaluate f(βˆ’x)f(-x) and compare it with f(x)f(x).
  • The function f(x)=x4βˆ’x3f(x) = x^4 - x^3 is not an even function.

Final Answer

Q: What is an even function?

A: An even function is a function where f(βˆ’x)=f(x)f(-x) = f(x) for all x in the domain of the function. This means that if we replace x with -x in the function, the function remains unchanged.

Q: How do I determine whether a function is even?

A: To determine whether a function is even, you need to evaluate f(βˆ’x)f(-x) and compare it with f(x)f(x). If f(βˆ’x)=f(x)f(-x) = f(x), then the function is even.

Q: What is the correct way to determine whether f(x)=x4βˆ’x3f(x) = x^4 - x^3 is an even function?

A: The correct way to determine whether f(x)=x4βˆ’x3f(x) = x^4 - x^3 is an even function is to evaluate f(βˆ’x)f(-x) and compare it with f(x)f(x). This is option C in the previous article.

Q: Why is f(x)=x4βˆ’x3f(x) = x^4 - x^3 not an even function?

A: f(x)=x4βˆ’x3f(x) = x^4 - x^3 is not an even function because f(βˆ’x)f(-x) is not equivalent to f(x)f(x). When we substitute βˆ’x-x into the function, we get f(βˆ’x)=x4+x3f(-x) = x^4 + x^3, which is not equal to f(x)=x4βˆ’x3f(x) = x^4 - x^3.

Q: What are some common characteristics of even functions?

A: Even functions have several common characteristics, including:

  • Symmetry about the y-axis
  • Even powers of x
  • f(βˆ’x)=f(x)f(-x) = f(x) for all x in the domain of the function

Q: Can a function be both even and odd?

A: No, a function cannot be both even and odd. If a function is even, then f(βˆ’x)=f(x)f(-x) = f(x) for all x in the domain of the function. If a function is odd, then f(βˆ’x)=βˆ’f(x)f(-x) = -f(x) for all x in the domain of the function. These two properties are mutually exclusive.

Q: How do I determine whether a function is odd?

A: To determine whether a function is odd, you need to evaluate f(βˆ’x)f(-x) and compare it with βˆ’f(x)-f(x). If f(βˆ’x)=βˆ’f(x)f(-x) = -f(x), then the function is odd.

Q: What is the relationship between even and odd functions?

A: Even and odd functions are related in that they can be combined to form a new function. Specifically, if f(x)f(x) is an even function and g(x)g(x) is an odd function, then f(x)+g(x)f(x) + g(x) is an odd function, and f(x)βˆ’g(x)f(x) - g(x) is an even function.

Q: Can you give an example of an even function?

A: Yes, a simple example of an even function is f(x)=x2f(x) = x^2. When we substitute βˆ’x-x into the function, we get f(βˆ’x)=(βˆ’x)2=x2f(-x) = (-x)^2 = x^2, which is equal to f(x)f(x). Therefore, f(x)=x2f(x) = x^2 is an even function.

Q: Can you give an example of an odd function?

A: Yes, a simple example of an odd function is f(x)=x3f(x) = x^3. When we substitute βˆ’x-x into the function, we get f(βˆ’x)=(βˆ’x)3=βˆ’x3f(-x) = (-x)^3 = -x^3, which is equal to βˆ’f(x)-f(x). Therefore, f(x)=x3f(x) = x^3 is an odd function.