How do you use the Squeeze Theorem to show that sqrt (x) * e^(sin(pi/x))=0xesin(πx)=0 as x approaches zero?

1 Answer
Oct 11, 2015

-1 <= sin(pi/x) <= 11sin(πx)1 for all x != 0x0.

So, e^-1 <= e^sin(pi/x) <= e^1e1esin(πx)e1 for all x != 0x0.
(e^ueu is an increasing function)

For x > 0x>0, sqrtxx is defined and positive, so

sqrtx/e <= sqrtxe^sin(pi/x) <= e sqrtxxexesin(πx)ex

lim_(xrarr0^+)sqrtx/e =0 " " and " " lim_(xrarr0^+)esqrtx =0.

Therefore, by the Squeeze Theorem,

lim_(xrarr0^+)sqrtxe^sin(pi/x) =0