How Do You Graph xcos(1/x) by Hand?

  • Thread starter Thread starter JamesBwoii
  • Start date Start date
  • Tags Tags
    Graph
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
1 reply · 3K views
JamesBwoii
Messages
71
Reaction score
0

Homework Statement


Draw a graph of xcos(1/x)2. The attempt at a solution

I've differentiated the equation using the product rule.

This got me to:

cos(1/x) + sin(1/x)/x

What I don't know how to do is actually go about drawing the graph. This is also a past paper question for an exam where I won't be allowed calculators.

Thanks!
 
Physics news on Phys.org
JamesBwoii said:

Homework Statement


Draw a graph of xcos(1/x)


2. The attempt at a solution

I've differentiated the equation using the product rule.

This got me to:

cos(1/x) + sin(1/x)/x

What I don't know how to do is actually go about drawing the graph. This is also a past paper question for an exam where I won't be allowed calculators.

Thanks!

Calculators won't help you with that.

(1) [itex]-x \leq x\cos(1/x) \leq x[/itex].
(2) [itex]\cos(1/x) \to 1[/itex] as [itex]x \to \infty[/itex].
(3) How fast does [itex]\cos(1/x)[/itex] oscillate at [itex]x \to 0[/itex]?