Asked by Bradley

Evaluate giving exact values and identities. Calculator based solutions are not acceptable. Thanks for any help

sin (-pi/12)
Answered by Ms. Sue
Carmen, Bradley -- please use the same name when you post similar questions.

Also -- does your instructor accept answers from anonymous people on the internet?
Answered by Bradley
yes
Answered by Damon
well pi is 180 degrees
180/12 = 15
so we really want sin(-15 degrees)
But I know that sin 30 = 1/2
and that cos 30 = (1/2) sqrt 3
and I know how to find the sine of half an angle if I have the cosine of the whole angle
Answered by Reiny
sin(-15)º = sin(30-45)º

can you take it from there?