I have defined a function q(t) in Maple as:

I then calculate it's 15th (!) derivative and assign it a name:

I wish to maximize this function on the domain [0,50], so do the following:

But this just throws out an expression rather than a particular maximum value.
I thought perhaps I need to use eval() on the derivative, so did the following:

However, this throws out a huge expression as well.
How would I use Maple to output the exact maximum value for this function? I'm sorry if this is unclear, I am pretty new to Maple and also to this website, so please accept my apologies in advance but know that I am willing to learn!