2—2 2元 is (at)cos kotd cat) sin kotI=0 Ak=bx 2 +aK b Kk兀 (K为奇数) yx= arctan K 0 b K Z的展开式为 2 m(sin at+sin 3at +=sin 5at +. 2兀 3 (以理步交通大学sin 0 2 1 ( )cos ( ) 2 0 2 0 =  = =          k t k I a i t k td t m k S k I A b a b m K K K K 2 2 2 = + = = （K为奇数） = arctan = 0 K K K b a  s i 的展开式为： sin5 ) 5 1 sin3 3 1 (sin 2 2 = + t + t + t + I I i m m S    