- #1
physman55
- 13
- 0
Homework Statement
Homework Equations
[tex]\frac{\delta{F}}{\delta{y}} - \frac{d}{dx}\frac{\delta{F}}{\delta{y'}} = 0[/tex]
The Attempt at a Solution
I'm having trouble setting this one up. If I let the functional be
[tex]F(x,x',y) = n(y)\sqrt{1+(x')^2}[/tex]
Applying the LE equation I obtain:
[tex]\frac{d}{dy}\frac{x'}{\sqrt{1+(x')^2}}n_0(1-\frac{y^2}{a^2})=0[/tex]
And this is where I stopped (I haven't used either of the hints). Any hints?