Solving an Internal Indeterminate Truss Problem

[fonseh]

Homework Statement

In this problem , it's a Internal Indeterminate truss .

Homework Equations

The Attempt at a Solution

So , I remove one of the redundant member , AC and solve the problem .
For the first part , I found the real force first . for the second part , I apply the virtual unit force at AC ...I gt my ans = 2.28 , but the ans given is 1.62 . I have checked thru my working many time s, yet I still can't find my mistake , can someone help please??

 

[fonseh]

Is my question not clear enough or i am posting at the wrong section ?