题目如下图 隐函数求导

求 详细过程

第1个回答  2011-10-29
解:∵(x²+2y)³=2xy²+64
==>3(x²+2y)²(2x+y')=2(y²+2xyy') (等式两端对x求导数)
==>6x(x²+2y)²+3(x²+2y)²y'=2y²+4xyy'
==>[3(x²+2y)²-4xy]y'=2y²-6x(x²+2y)²
∴y'=[2y²-6x(x²+2y)²]/[3(x²+2y)²-4xy]
第2个回答  2011-10-30
解:∵(x²+2y)³=2xy²+64
==>3(x²+2y)²(2x+2y')=2(y²+2xyy') (等式两端对x求导数)
==>6x(x²+2y)²+6(x²+2y)²y'=2y²+4xyy'
==>[6(x²+2y)²-4xy]y'=2y²-6x(x²+2y)²
∴y'=[2y²-6x(x²+2y)²]/[6(x²+2y)²-4xy]
=[y²-3x(x²+2y)²]/[3(x²+2y)²-2xy]本回答被提问者采纳