Find the exact value of this expression:

sin (-105°)


I've found multiple solutions online for sin (105°) but not sin (-105°), please help.
Please show work if possible. I'm getting right numbers but my positive / negative symbols are off and I don't know why.

You should know that \sin(x) = - \sin(-x).

Don't quote me, but this might work...

Sin(-105) = ?
105 = 60 + 45
0 - 105 = -105
you could use
Sin(0-105) = Sin(0)Cos(105) - Sin(105)Cos(0)
and since sin(0)=0 and cos(0)=1
= -Sin(105)
-(sin(60 + 45)) = -(Sin(60)Cos(45) + Sin(45)Cos(60))

Does this Help?