Question

PLEASE HELP!!!!

Answer 1

btw I have no trig background besides SOHCAHTOA

Answer 2

sin(210)=sin(180+30)=sin180 cos30 + cos180 sin 30

can you do it from here ?

Answer 3

… can you go step by step please?

Answer 4

so it is c. because sin(210)=sin(pi + 30) = - sin 30

Answer 5

and we have this general rule that says: sin (pi + a) = - sin a

Answer 6

OK
\(\LARGE\color{blue}{ \bf sin(a+b)=sin(a)cos(b)+cos(a)sin(b) }\)
is one of the rules that is used to solve for angles such as 210, 450, 275 and etc.
we are splitting the angle into 2 more known values,
see how I am splitting 210?

\(\large\color{blue}{ \bf sin(210)=sin(180+30)=sin(180)cos(30)+cos(180)sin(30). }\)

Answer 7

\(\normalsize\color{blue}{ \bf sin(210)=sin(180+30)=sin(180)cos(30)+cos(180)sin(30). }\)

Answer 8

also note that sin (-a) = - sin (a)

Answer 9

See? I have split 210 into 2 known values,

you know that sin180=0 right? so ignore the first part, you are left with

cos(180)sin(30)
cos180=1
sin 30= a /2a =1/2