Originally Posted by

**abc10** Just a word problem thats bugging me:

The height, in metres, of a nail in a water wheel above the surface of the water, as a function of time, can be modelled by: h(t)=-4sin pi/4 (t-1) + 2.5 where t is time in seconds. During what periods of time is the nail below the water in the first 24 s that the wheel is roatating...

There is a similar proble, in the book which outlines how you would solve it, except that there are no brackets (where the t-1 is) so this is throwing me off, because I don't know how to get to the next step after that and everything i've tried has been wrong.

Thanks a lot in advance!