Plot won't plot the solution to my differential equation

Questions
1

I have this expression:

testsprog = DSolve[{feq, y[1] == 1}, y[x], x]

That, upon evaluation, produces:

{{y[x] -> 1/2 x Tan[2 (ArcTan[2]/2 + Log[x])]}}

When I try to plot it using the command:

Plot[testsprog, {x, 1, 4}]

I see only a coordinate axis, and not my equation. Why?

2 
Plot[ Evaluate[ y[x] /. testprog ], {x, 1, 4}]

The Evaluate is to prevent Plot from evaluating the expression separately for every point.

3

Please see this short tutorial on using the output of fucntions like Solve, NSolve, and DSolve:

http://support.wolfram.com/kb/3825