更新时间2019-02-17 14:27:00
解:(17) ∫{[2^(x+1)-5^(x-1)]/10^x}dx
=∫[2/5^×-1/5·2^x]dx
=2∫5^(-x)dx-(1/5)∫2^(-x)dx
=2·(5^-x)/ln5-(1/5)·2^(-x)/ln2+C
=2/5^x·ln5-1/5·2^x·ln2+C
(18) ∫{√[x⁴+x^(-4)+2]/x³}dx
=∫{√[x²+x^(-2)]²/x³}dx
=∫{[x²+x^(-2)]/x³}dx
=∫(1/x)dx+∫x^(-5)dx
=ln|x|-x⁴/4+C