you have to use the identities an. It's trig
(Sec theata+ Csc theata)(cos theata+ sin theata)
(Sec x + Csc x)(cos x+ sinx) ..... I used x instead of theata
= [1/cos x + 1/sinx] (cosx +sinx)
= [(sinx+ cosx)/cosxsinx]/ (cosx+sinx)
=(1/cosx)x(1/sinx)= Secx Cosecx
Now you can replace theata for x.
The first step is to FOIL the equation, i.e. (a + b) (c + d) = ac + ad + bc + bd.
Once you do that, I would suggest you look at the relationship between sin & csc and cos & sec, which should simplify some of those 4 terms.
With that done, you should have some fractions left, so I would try creating a common denominator and seeing if any thing reduces further using the sin^2 + cos*2 = 1 identity.
If any of these suggestions does not make sense, please feel free to email me or ask a follow-up questions. John