Recent content by fionamb83

Hi, I'm not sure if this is on the right thread but here goes. It's a perturbation type problem. Consider the boundary value problem $$\epsilon y'' + y' + y = 0$$ Show that if $$\epsilon = 0$$ the first order constant coefficient equation has the solution $$y_{outer} (x) = e^{1-x} $$...

Hi, I'm not sure if this is on the right thread but here goes. It's a perturbation type problem. Consider the boundary value problem $$\epsilon y'' + y' + y = 0$$ Show that if $$\epsilon = 0$$ the first order constant coefficient equation has the solution $$y_{outer} (x) = e^{1-x} $$ I have...

Sorry just saw what I did there. Oops. the x derivative of y/x is -y/x^2. Sorry confused myself there. Thanks for the help everyone!

so df/dx = -2x/1+y^2 ?

Homework Statement For the function of two variables f(x,y)=tan^-1(y/x) find df/dx and df/dy I know i just differentiate with respect to x and then to y but I'm stuck on the tan^-1(y/x) I know tan^-1(x)=1/1+X^2 when I applied this with respect to x I get 1/-1+y I think this is wrong...

I = I_0 \cos^2 30^o From Cutnell, Physics

Got it! I feel silly! I realize equation I was trying to use was wrong. I solved it using Malus' Law intensity after = Intensity before*cos^30 Thanks for the quick reply tho.

Two sheets of polaroid are oriented so that there is a maximum transmission of light. One sheet is now rotated by 30 degrees, by what factor does the light intensity drop? OK, the only equation I could think to use is tanB = N1/N2 but it doesn't seem to work. the answer is 0.75 I...