Planar Kinematics of Rigid Bodies - Relative Motion

[aolse9]

Homework Statement

http://www.hdimage.org/images/bgkkpt63ckx96gu3xgh.jpg

Homework Equations

a_A = a_A/B + a_B

V_A = V_A/B + V_B

The Attempt at a Solution

After staring at this question for some time, I finally had a go and got an answer of 1.25 rad/s, which is incorrect. I am totally lost and need some help, any assistance would be great!

 

[aolse9]

Any ideas?