Help me out? My answer doesn't seem to be correct?

Question

anonymous · Answer

when I work it out I get: $$\sin^{2}a+\cos^{2}a$$ But that isn't in the answer choices. I'm very confused.

anonymous · Answer

first off, without even looking, if it is 
$$\sin^2(x)+\cos^2(a)$$ then it is $1$

anonymous · Answer

Yeah, that's what I was thinking--that it simplified into that fundamental identity, but apparently I've gone wrong somewhere.

anonymous · Answer

no you have not
this question was written by a moron
one of those other answers is 1 also
we just have to figure out which one it is

jim_thompson5910 · Answer

anonymous · Answer

Thank you, you were right, sec^2a-tan^2a was equal to 1. It was just trying to trip me up. Thank you so much.

jim_thompson5910 · Answer

yeah making something more complicated than it has to be, but they just want to make sure you're awake I guess

jim_thompson5910 · Answer

choice D is correct

anonymous · Answer

yeah that is the right one
but you could also pick 
$$\frac{2\times 3+5}{11}$$

anonymous · Answer

sometimes math teacher write amazingly dumb questions 
pity