I'm in Calculus 3 and were going over unit tangent vectors, normals, and curvature this chapter. I'm in the middle of doing one of those said problems now. I found the unit tangent vector, now I have to find the normal. So I started doing it and (by the way my homework is done all online through a program called MyMathLab) it said "Although my answer is correct, it is not in the correct form". Can someone please help me simplify this thing? Or help me get in the correct form. It really is bothersome.

Edit: It seems this is the correct answer. Anyone know how to obtain it from my answer which is also correct but not in the right form?