Symbolic toolbox in Mathcad 14

Hi guys, I am very new to Mathcad, more of a Matlab user. I heard Mathcad is better for symbolic maths, and its rather hard to solve exponential equations in Matlab symbolic toolbox.

I have seen a few tutorial, read the guide book, but nothing works. I know I am missing something. I have attached the worskheet with simple derivative, it also shows emission failure or pattern match exception message. I just want to learn on how to solve it. Additionally, I cant access the Variable, Matrix and Transform options under Symbolics option.

Please advice guys.

P.S: I learnt the basic of Mathcad with sine wave plotting and so on. Its just symbolics killing me now.