求教lim x→0 ( cos x / cos2x )^(1/x^2)

lim(x→0)(1-cos2x)/xsinx 极限x→0 lim[(cosx-cos2x)/x^2] 求lim(x→0)x cos 1/x lim(x→∞)x^2/ (3x-1)的极限 2.5计算极限lim(x→0) (1-cos2x)/xsinx 求极限 lim(x→0){(cos2x-cos3x)/[(1+x^2)-1]} 求lim(x→0)〔1-cos2x+tan^2 X〕/xsinx lim(cosx+cos2x+ cos3x+…+ cos nx-n)/(cosx-1) (x趋于0) lim x→0 sin2x/sin5xlim x→0 (1-cos2x)/x²lim x→0 in(1-x/2 1.lim(x→0)1-cos2x/x*sinx [x和sinx是一起的] cos^2 x=(cos2x-1)/2 lim(x→0)[cos√(1-x^2)]/[tanx*ln(1+x)] 求lim(x→0+） ( 2/π*cosπ/2(1-x))/x的极限