几道数学分析题：1.lim(x→0) (cosx-cos3x)/x^2=lim(x→0) (2sinxsin2x)/x^

lim(cosx-cos3x)/(5x) x趋向0 求极限：lim(x→0）(1/x^2)[1-cosx(cos2x)^(1/2)(cos3x)^(1/3)...(cosn lim x→0 (1-cosx√cos2x√cos3x)/(e^x+1)sinx dx 请问lim x→0 (cosx-cos3x)/x的平方等于? 三道极限题1. lim(x->0) [1-cosx√cos2x(3^√cos3x)]/x^2的极限2. 当x->0+时 已知lim(x→0) f(x)/(1-cosx) =2 求lim(x→0) [1+f(x)]^½ lim(x→0)(1/cosx)=? lim(x→0)(cosx)^(1/ln(1+x^2)) lim(x→0)(ln(1+x^2)/(sec-cosx)) lim(x→0)(cosx)^[4/(x^2)] lim x→0[ln(cosx)]/x^2 极限x→0 lim[(cosx-cos2x)/x^2]