Question

对数求导法能否用于隐函数的求导?

Answer 1

可以啊

比如

y^x = x^y

xlny = ylnx

d(xlny) = d(ylnx)

lnydx + (x/y)dy = lnxdy + (y/x)dx

[lnx - (x/y)]dy = [lny - (y/x)]dx

dy/dx = [lny - (y/x)]/[lnx - (x/y)]