Question

find the exact value : sin (-620 degrees)

Answer 1

sin(-620) = sin(720-620) = sin(100)

Answer 2

why does 720 subtract from 620

Answer 3

Because 720 is two complete revolutions.

Answer 4

And you want to find the reference angle

Answer 5

and 100 ends up being the exact value?

Answer 6

sin(100)=sin(80)= exact value.

Answer 7

Are you sure you didn't make a typo?

Answer 8

wait a minute, yes its 630 degrees.

Answer 9

Is it negative 630?

Answer 10

yes still negative
it says follow the even- odd properties

Answer 11

it was an exam question i got wrong, and i put -1 as an answer because i thought it was sin 90 degrees..i used my calculator to answer

Answer 12

I don't know what you mean by the even-odd properties but ...Start with -630 add 360 so now you are back at your starting point and still have -270 degrees to go. That brings you to 90 degrees and the sin is 1