I know from my text that tanx=1 when x=npi + pi/4 where n is and integer.

The text does not say how one should deduce that however (it's a caluclus text and perhaps this should be known from precalc?)

In any case, besides memorizing the values of x that make tanx=1, how would I got about finding these values algebraically? Or is it something that one really should memorize in the early stages?

thanks