大學(xué)求極限

1
lim[(a^x+b^x+c^x）/3]^(1/x) {a,b,c,都大于0;x→0}
=lime^{[ln(a^x+b^x+c^x）襲蘆/寬帆3]/x)}
=lime^[(lna*a^x+lnb*b^x+lnc*c^x)/(a^x+b^x+c^x)]
=lime^[[ln(abc)]/3]
=(abc)^(1/3)
2
lim(sinx)^tanx{x→π/慎禪雹2}
=lime^[(lnsinx)/cotx]
=lime^[(cosx/sinx)/(-csc2x)
=lime^（-sinxcosx）
=1