[SOLVED] Trig functions, exponents of trig functions, and tring stunt variables

Here I go...

(Thinking)

What's the difference between sin^2(x), (sinx)^2 and sin(x)^2

What does it mean when the 2 is in each one of these positions?

Is this right? sinx * sinx = (sinx)^2? or is it sin^2x?

Why is it that we can simplify some trig functions like

sin2x/2x into siny/y, but when we put a radian value in for x in the first expression it doesn't equal to the same this when we put that value in for y? I think this is using stunt variable but I'm unsure why we can use these things are true equations to find other answers (i hope this question made a little bit of sense)?

Also what's the difference between F(x) and f(x)?

THANKS FOR YOUR HELP.