# Pre Calculus

posted by on .

ok I appologize for my stupidity...

ok instructions to this problem

In problems 77-88, use properties of the trigonmetric functions to find the exact value of each expression. Do not use a calculator

85. sin(-pi/12)csc( (25 pi)/12 )

book dosen't say weather or not if it's in radians but I assume it is...

Ok I just put it into my calculator and got negative one I'm in radian mode...

Here's what I put in my calculator...

(sin(-pi/12))/(sin((25pi)/12))

My back of the book, sense this is an odd problem gives me also -1 here's why...

when you added pi to the denomenator you forgot to make it negative...

this would give you negative one

ok

I have a question

why is sin(-20)/cos 380

= to tan of -200

I know sin over cos is tan just don't see were the -200 came from thanks!

• Pre Calculus - ,

see...

(- sin pi/12 + pi)/(sin (25 pi)/12 + pi)

this becomes

(sin pi/12 + pi)/(-sin (25 pi)/12 + pi)

finish it off and you get negative one...

why is sin(-20)/cos(380) equal to tan(-200)

I don't understand