Truss - Method of Joints in terms of load P

[opensourcery]

Hello guys. I would like someone to check that I am doing this problem correctly. The answer given in the book is 0.577(P) for F_AB and F_AE which differs from the answer I get.

Homework Statement

Determine the force in each member of the truss in terms of the load P and state if the members are in tension or compression.
Drawing with work http://imagebin.org/232748

Homework Equations

$\Sigma$M_A = 0
$\Sigma$F_x = 0
$\Sigma$F_y = 0

The Attempt at a Solution

Entire truss system

$\Sigma$M_A = 0
-L(P) + 2(L)(D_y) = 0
D_y = $\frac{P}{2}$

$\Sigma$F_x = 0
A_x = 0

$\Sigma$F_y = 0
A_y - P + D_y = 0
A_y = $\frac{P}{2}$


Forces at pin A

$\Sigma$F_y = 0
A_y - $\frac{1}{\sqrt{2}}$(F_AB) = 0
F_AB = $\frac{\sqrt{2}}{2}$(P)

$\Sigma$F_x = 0
-$\frac{1}{\sqrt{2}}$(F_AB) - F_AE = 0
F_AE = $\frac{-P}{2}$

 

[Valkarie]

+ \frac{\sqrt{2}}{2}(P) = \frac{-P}{2} + \frac{\sqrt{2}}{2}(P)Forces at pin B\SigmaFy = 0Ay + FBB = 0FBB = -\frac{\sqrt{2}}{2}(P)\SigmaFx = 0FBB - FBC - \frac{1}{\sqrt{2}}(FAB) = 0FBC = \frac{-3P}{2} + \frac{\sqrt{2}}{2}(P)Forces at pin C\SigmaFy = 0Ay + FBC = 0FBC = -\frac{\sqrt{2}}{2}(P)\SigmaFx = 0FBC - FCD = 0FCD = \frac{-P}{2} + \frac{\sqrt{2}}{2}(P)Forces at pin D\SigmaFy = 0Ay + FCD = 0FCD = -\frac{\sqrt{2}}{2}(P)\SigmaFx = 0FCD - FDG = 0FDG = \frac{-P}{2} + \frac{\sqrt{2}}{2}(P)Forces at pin E\SigmaFx = 0FAE + FEH = 0FEH = \frac{-P}{2} + \frac{\sqrt{2}}{2}(P)\SigmaFy = 0Ay + FEG = 0FEG = -\frac{\sqrt{2}}{2}(P)Forces at pin G\SigmaFx = 0FDG + FGJ = 0FGJ = \frac{-P}{2} + \frac{\sqrt{2}}{2}(P)