This one makes my brain spin:

Find the derivative:

$\displaystyle y = \sqrt{x + \sqrt{x + \sqrt{x}}}$

I see four composed functions here (sorry I'm running out of letters at the end):

$\displaystyle y = f(u) = \sqrt{u}$

$\displaystyle u = g(x) = x + \sqrt{x}$

$\displaystyle x = h(t) = t + \sqrt{t}$

$\displaystyle t = z(v) = \sqrt {v}$

Since I probably have already made a mistake, I'll just stop here for now to see what people think of this.

Thanks.