Question

x÷根号下2+4x的不定积分换元法和分部都可以吗，我算了两个答案不一样

Answer 1

问：x÷根号下2+4x的不定积分换元法和分部都可以吗，我算了两个答案不一样

答：(1-3x)^(7/3) / 21 - (1-3x)^(1/3) / 12 = (1-3x)^(4/3) ((1-3x)/21 - 1/12)= (1-3x)^(4/3) * (-1/28 - x/7)-x/4 * (1-3x)^(4/3) - (1-3x)^(7/3) / 28 = (1-3x)^(4/3) (-x/4 - (1-3x)/28 )=(1-3x)^(4/3) * (-1/28 - x/7)因此,两个答案相同.