
Re: [微積] 請教這過程怎麽來的

(2y/x^2)'
=[(x^2)(2y')-(2x)(2y)]/(x^4)...quotient rule
=[(x)(2y')-4y]/(x^3)
(2y/x^2)''
={(x^3)(2y'+2xy''-4y')-(3x^2)(2xy'-4y)]/(x^6)...再用一次"除微"
=(2x^2y''-8xy'+12y)/(x^4)
=(2/x^2)y''-(8/x^3)y'+(12/x^4)y
這些
還可再翻calculus
複習一下...
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05/10 13:45, , 1F
05/10 13:45, 1F
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