Question

find the exact value : sin (-620 degrees)

Answer 1

are u sure that is -620 ?

Answer 2

yes

Answer 3

I already know it equals into 100 degrees, what I don't understand it actually finding the exact value for sin100 degrees.

Answer 4

yeah, 100 is not the special degrees.. need to long time to get its exact

Answer 5

I don't quite understand what your saying, I'm talking about Sum and Difference Identities.

Answer 6

i think u want simplify it by using Sum or Difference Identities, right ?
sin(-620) = -sin(620) = -sin(2*360-100) = -sin(-100) = (-)(-)sin(100) = sin100
if u want simplify again, it can be
sin100 = sin(90+10) = -cos10

Answer 7

It's +100, not -100

Answer 8

10 degree is not the special angle too, in trigono
we can getting its exact value, but too longgggg :)

Answer 9

\(-620^\circ + 2\cdot 360^\circ = 100^\circ \)

Answer 10

i used identity sin(-x) = -sinx, first
@wio

Answer 11

Sorry I think I wasn't clear about this question at the start. I have to use the formula:
"sin(a +B) = sina cosB + cosa sinB " to find the exact value of 100 degrees

Answer 12

I can't use values such as 30, 45, or 60 degrees because they don't equal to 100 degrees

Answer 13

When you try to add 2 of them to eachother

Answer 14

yes, we cant use 30,45,60 deg!
better searching google :)

Answer 15

I did! Which resulted hurting my hand from smacking it against my desk...

Answer 16

maybe, this file useful for u

Answer 17

and if ur question is -630 not -620, we can get it
sin(-630) = -sin(630) = -sin(360+270) = -sin(270) = -(-1) = 1