Question

Find the value of the following using the concepts of both addition and subtraction formulas and reference angle:

sin 255

Answer 1

@eliassaab

Answer 2

@ganeshie8

Answer 3

@Callisto

Answer 4

\[
\sin (225)=-\sin (360-255)=-\sin (105)=-\sin (45+60)=\\-\sin (45)) \cos
(60)-\sin (60) \cos (45)
\]

Answer 5

\[
-\sin (45)) \cos
(60)-\sin (60) \cos (45)=-\frac{1+\sqrt{3}}{2 \sqrt{2}}
\]

Answer 6

why is it -sin(360-255)

why the - sign there?

Answer 7

\[
-\sin(360-255)=- \sin (-255) =-(-\sin( 255)) = \sin(255)
\]

Answer 8

Did you understand it?

Answer 9

no
sorry where did you get that?

Answer 10

If you add 360 to an angle you do not change the sine of that angle
sin(360+y) = sin(y)
sin( 360 +(-x)) =sin(-x) = -sin(x)
If you do not know these elementary facts, please review them in your book or notes.

Answer 11

Have you heard about periodic functions?

Answer 12

have no heard of periodic functions ever @eliassaab