- #1
AATroop
- 31
- 2
Homework Statement
Solve [itex]x^{2}\times y'' - 4 \times x \times y' + 6 \times y = 0[/itex] for [itex]y(x)[/itex] by first using the substitution [itex]v = ln(x)[/itex] to obtain an equation involving [itex]y, dy/dv, d^2y/dv^2[/itex] and no [itex]x[/itex]. Solve for [itex]y(v)[/itex], then return to [itex]y(x)[/itex].
Homework Equations
NA
The Attempt at a Solution
I know how to solve the differential once I substitute in for [itex]v[/itex], but what I'm not getting right is the substitution for the derivatives. I know [itex]dy/dx = dy/dv \times dv/dx = dy/dv \times \frac{1}{x}[/itex], but what I can't figure out is [itex]d^2y/dx^2[/itex]. I got [itex]-dy/dv \times \frac{ln(x)}{x^2}[/itex], but that's not giving me the right answer (I checked w/ Wolfram Alpha). So, I'm a bit stuck on that.
Any help is appreciated, thanks.