lim(x→0）(1+sinx)＾1/sin2x
=lim(x→0）(1+sinx)＾1/(2sinxcosx)
=lim(x→0）(1+sinx)＾1/(2sinx)
=lim(x→0）[(1+sinx)＾1/(sinx)]^(1/2)
=e^(1/2)