1−x1exsinxcosxarctanxln(1+x)(1+x)k=n=0∑∞xn=1+x+x2+x3+…=n=0∑∞n!xn=1+1!x+2!x2+3!x3+…=n=0∑∞(−1)n(2n+1)!x2n+1=x−3!x3+5!x5−7!x7+…=n=0∑∞(−1)n(2n)!x2n=1−2!x2+4!x4−6!x6+…=n=0∑∞(−1)n2n+1x2n+1=x−3x3+5x5−7x7+…=n=1∑∞(−1)n−1nxn=x−2x2+3x3−4x4+…=n=0∑∞(k)xn=1+kx+2!k(k−1)x2+3!k(k−1)(k−2)x3+…