没有显式积分式,可展开为泰勒级数再积分,如展开为x+1/3*x^3+3/10*x^5+16/63*x^7+727/3240*x^9
积分,得=1/2*x^2+1/12*x^4+1/20*x^6+2/63*x^8+727/32400*x^10