LINT

(x) ≥ x for all x in R.... so the function has no domain.

we need (sinx) ≥ (cosx)

consider first quad..
all values satisfy. (except x=0)

consider second quad ..
all values satisfy

consider third quad...
all values satisfy (except x=3pi/2)

consider 4th quad.
no value satisfies..'

so domain
(2n pi, 2n pi + 1.5 pi)

thx..Q2 was a bit confusing..but now done..

LINT = Least Integer Function...opposite of Greatest Integer Function..
LINT = Greater than or equal to..
so for example Lint of 2.3 = 3.... : )