[微積] 請教一下這兩題

[tansun (墮落研究生)]

http://imgur.com/K9qozMO
如圖~請教一下這兩題微分方程式如何解~裡面的字寫錯了~不好意思
謝謝各位囉~

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推 carelai     : Let z=y' and u=z/x, then you will have u''=1/x^6
→ carelai     : solve for u, and you get expression for y.
→ carelai     : the above is for question 1.
推 carelai     : For question 2, first solve homegeneous equation
→ carelai     : y''+4y=0, this is easy.
推 carelai     : Sorry, for question 1 should be u''=x^(-7)