x→+∞lim [(2/π)arctanx]^x=lim e^ln [(2/π)arctanx]^x=e^lim ln[(2/π)arctanx]^x考虑lim ln[(2/π)arctanx]^x=lim x * ln[(2/π)arctanx]=lim ln[1+(2/π)arctanx-1] / (1/x)=lim [(2/π)arctanx-1] / (1/x)该...