I gave an example here: http://vcenotes.com/forum/index.php/topic,31595.msg326494.html#msg326494
see this question about strictly increasing/decreasing was even on my uni pure maths exam!
That don't even make sense to me 
ok let me try explain it.
a strictly increasing function is a function such that if you pick any value a and b in its domain where a<b then f(b) > f(a)
now say we have a parabola, y = x^2, look at the origin. if we pick a = 0 and b = 1, then clearly f(b) > f(a) so we INCLUDE a = 0
strictly increasing has NOTHING to do with the gradient being 0 or whatever, at x = 0 in y=x^2 we clearly have dy/dx = 0, but we still include the point x =0 since it satisfies the
definition of strictly increasing.
mathematics is built on
definitions, follow them or you're wrong

get it now? or need further explanations?