题目内容：

几道求不定积分的题,
1,∫ 1/( (x-2)^2*(x-3) ) dx
2,∫ sinx * sin2x * sin3x dx
3,∫(x^2 - 5x + 9) / ( x^2 - 5x +6 ) dx
4,∫ cosx / ( sinx( 1 + sinx)^2 ) dx
1,1/(x-2) + In| (x-3)/(x-2)| + c
2,1/8*(1/3 * cos(6x) - 1/2 * cos(4x) - cos(2x)) +c
3,x+3In|(x-3)/(x-2)| +c
4,In|sinx/(1+sinx)| + 1/(1+sinx) +c