Why Am I Struggling with This Math Problem?

[Matt1234]

1. The problem and attempt statement, all variables and given/known data

[PLAIN]http://img31.imageshack.us/img31/2530/lastscanph.jpg



I have been at this problem for a while and i can't seem to find where i am going wrong, can someone please take a look at it.
thank you for your time.

 

[PhanthomJay]

1. The problem and attempt statement, all variables and given/known data

I have been at this problem for a while and i can't seem to find where i am going wrong, can someone please take a look at it.
thank you for your time.

Say hey, Matt, I'd like to first congratulate you on your 100th post! .

Another 20,000 more and you'll catch up to our beloved Doc Al

Your calculation for F_AB is excellent. But you get into trouble when you choose the beam as the x-axis when using sum of forces in x direction = 0. Keep the x-axis as the horizontal axis. Then the weight of the beam and the weight of the load, which act vertically down, have no x components. Only the tension cable force and the R horizontal reaction force (Rx) have x components. And the x component of F_AB will be ?

 

[Matt1234]

Thank you very Jay, this is a fantastic site.
I followed your suggestion, and finally got the answer. Thank you for your help :)