Can the Chain Rule Prove Even and Odd Symmetry in Derivatives?

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In summary, the conversation is about using the chain rule to verify that if a function has even symmetry, its derivative function has odd symmetry and vice versa. The participants are discussing strategies for proving this relationship holds for all even and odd functions on the set of real numbers.
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PerenialQuest
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Hello all,
This is a question on a problem set for my Calculus 1 class. Please help if you can.

Homework Statement


A function, f defined on the set of real numbers is said to have even symmetry if f(-x) = f(x) for all x, and is said to have odd symmetry if f(-x) = -f(x) for all x. Use the chain rule to verify that if a function has even symmetry, its derivative function has odd symmetry and vice versa. Note that I am asking you to show that this is true in general. You cannot simply cite examples, such as the fact that f(x) = x^2 has even symmetry and its derivative function f'(x) = 2x has odd symmetry. You must show that this relationship holds for all even and odd functions on the set of real numbers.

Homework Equations



Chain rule: [d/dx] f(g(x)) = f'(g(x)) * g'(x)

The Attempt at a Solution


I would love to attempt this, but I do not know where to begin. I see that this conjecture is clearly true in any specific example like the one mentioned above, but I do no know how to go about proving this in general. If someone can just suggest a strategy I can probably figure it out or I can at least try it and return with evidence of a concerted effort.

Thanks for the help. Richard
 
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  • #2
Pick g(x)=(-x) in the chain rule. Then try and start something from there.
 

FAQ: Can the Chain Rule Prove Even and Odd Symmetry in Derivatives?

What are derivatives?

Derivatives are mathematical tools used to measure the rate of change of a function with respect to its independent variable. They represent the slope of a curve at a specific point and are essential in many areas of science, including physics, engineering, and economics.

How are derivatives calculated?

Derivatives are calculated using the rules of differentiation, which involve finding the limit of a function as the change in the independent variable approaches zero. These rules include the power rule, product rule, quotient rule, and chain rule.

What is odd symmetry?

Odd symmetry is a property of functions that have symmetry about the origin, meaning that they are unchanged when reflected across the origin. These functions are characterized by having f(-x) = -f(x) for all values of x. Examples of functions with odd symmetry include the sine and tangent functions.

What is even symmetry?

Even symmetry is a property of functions that have symmetry about the y-axis, meaning that they are unchanged when reflected across the y-axis. These functions are characterized by having f(-x) = f(x) for all values of x. Examples of functions with even symmetry include the cosine and secant functions.

How are derivatives related to odd and even symmetry?

The derivative of a function with odd symmetry is a function with even symmetry, and vice versa. This is because the derivative measures the slope of a function, which is unchanged when reflected across the y-axis or origin. This relationship is useful in simplifying calculations and understanding the behavior of functions.

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