Because (1/x) tanx = e (tanxln (1/x))
Because lim tanxln( 1/x)
=lim -xlnx (because tanx~x)
=0
So lim (1/x) tanx = e 0 =1.
(2)
Because (sinx/x) (1/x 2)
=e^(( 1/x^2)ln(sinx/x))
but
Forest (1/x 2) ln (sinx/x)
= lim( 1/x^2)(sinx/x- 1)
(because ln (sinx/x) = ln (1+(sinx/x-1))
=lim (Sinks-x)/x 3
=- 1/6 (this step can be obtained by Taylor expansion or L'H?pital's law).
So the original formula = e (- 1/6)