kpolich's Avatar
kpolich 4
17 Asked
6 Answered
0 Best
0
No one has voted on this question yet :(
3 years, 5 months ago

If I have an inductive proof of function f, is f(infinity) also true?

Tip for best answer: M$2.00
Separate topics with commas, or by pressing return. Use the delete or backspace key to edit or remove existing topics.

You can leave an optional "tip" with Mahalo's virtual currency, Mahalo Dollars. If you are asking a difficult question that might require some research, or if you'd like a wide variety of feedback, a higher tip often leads to more answers to your question.

M$

What is Your Answer?

0
0
0

2 Answers

0
littlepea's Avatar
littlepea | 3 years, 5 months ago
4
Consider the function f : x -> f(x) = 1/x defined for positive x. you can show that f is positive (i.e. for all x > 0, f(x) > 0); in particular f(n) > 0 for all positive natural integers. However, f(infinity) = 0.
So this is not true here...

You can leave an optional "tip" with Mahalo's virtual currency, Mahalo Dollars. If you are asking a difficult question that might require some research, or if you'd like a wide variety of feedback, a higher tip often leads to more answers to your question.

M$

Report Abuse

Post Reply Cancel
1
bugsy's Avatar
bugsy | 3 years, 5 months ago
3
It depends on the function and it's complexity. If the function is made of components that do not respect a linearity towards infinity, then it is NOT true. However, if all it's components yield valid values as the function advances, it is true.

You can leave an optional "tip" with Mahalo's virtual currency, Mahalo Dollars. If you are asking a difficult question that might require some research, or if you'd like a wide variety of feedback, a higher tip often leads to more answers to your question.

M$
bugsy's Avatar
bugsy | 3 years, 5 months ago Report

Yet again, it depends on the function. It's about which parts form the function, as those parts (or composites) decide the truthfulness of f at infinity. Think only at the special functions like sin, cos, exp, tan, atan, sinh, cosh, ln. A combination of these functions may not subject to a successful proof of what you want.

spoon's Avatar
spoon | 3 years, 5 months ago Report

Add a couple of notches of respect for you... impressive answer

kpolich's Avatar
kpolich | 3 years, 5 months ago Report

I am not clear on why this is a valid answer. What type of complexity are you referring to?

To establish an inductive proof, I must show that some base case, say f(0) is true, and then show that if f(n) is true, then f(n+1) is true. Linearity need not apply. To give a trivial example, if I want to show that the function f(x) = x^2 is never negative for all x >= 0, I can create such an inductive proof, yet f is not linear.

My question is more of a number theory question, I believe. Certainly an inductive proof is support that f(n) is true for any ordinal number n, but infinite is not actually a number, so I am asking if an inductive proof is valid for establishing the truthfulness of f(infinity) .

Report Abuse

Post Reply Cancel

Learn something new with our FREE educational apps!

Private lessons in the comfort of your own home. Get back in shape or finally pick up a guitar with our great experts guiding you the whole way!
Learn Guitar
Learn Hip Hop
Learn Pilates