Question 886190
cosθ + sinθ = 2cosθ
<pre>
Add -cos&#952; to both sides of the equation

 cos&#952; + sin&#952; = 2cos&#952;
-cos&#952;          -cos&#952;
--------------------
        sin&#952; =  cos&#952;

Add -sin&#952; to both sides of the equation:

        sin&#952; =  cos&#952;
       -sin&#952; = -sin&#952;
       -------------
           0 =  cos&#952; - sin&#952; 

The answer is 0.  None of the above.

Edwin</pre>