Loading [MathJax]/jax/output/HTML-CSS/jax.js
Ask Your Question

Revision history [back]

click to hide/show revision 1
initial version

asked 10 years ago

ensaba gravatar image

Can sage help determine if |f(x)L|<ϵ is true?

Here's what I want to check:

Given f(x),ϵ>0,LR and N(ϵ)

is n>N(ϵ)|f(n)L|<3

true?

I thought I could accomplish this using symbolic expressions and assume(). This is what I've tried:

forget()
var('ep, n')
f(x)=1/(n+7)
N = (1/ep)-7


assume(ep>0)
assume(n>N)

show(abs(f(n)-0)<ep)
bool(abs(f(n)-0)<ep)

But the result of is False. What is the proper way to do this in Sage?

click to hide/show revision 2
No.2 Revision

Can sage help determine if $$ |f(x) $|f(x) - L | L| < \epsilon$$ \epsilon$ is true?

Here's what I want to check:

Given f(x),ϵ>0,LR and N(ϵ)

is n>N(ϵ)|f(n)L|<3

true?

I thought I could accomplish this using symbolic expressions and assume(). This is what I've tried:

forget()
var('ep, n')
f(x)=1/(n+7)
N = (1/ep)-7


assume(ep>0)
assume(n>N)

show(abs(f(n)-0)<ep)
bool(abs(f(n)-0)<ep)

But the result of is False. What is the proper way to do this in Sage?

click to hide/show revision 3
No.3 Revision

Can sage help determine if |f(x)L|<ϵ is true?

Here's what I want to check:

Given $f(x),\epsilon>0, L\in f(x), ϵ>0, $L\in \mathbb{R}$ and N(ϵ)

is N(ϵ), is $$n>N(\epsilon) \Rightarrow |f(n)-L | < 3$$

\epsilon$$ true?

I thought I could accomplish this using symbolic expressions and assume(). This is what I've tried:

forget()
var('ep, n')
f(x)=1/(n+7)
N = (1/ep)-7

 assume(ep>0)
assume(n>N)

show(abs(f(n)-0)<ep)
bool(abs(f(n)-0)<ep)

But the result of is False. False. What is the proper way to do this in Sage?