Question

How do I find out if this is an identity?

Answer 1

@Freez @freckles @Godlovesme @zoejay1 @Phebe @wallacekali @KitKat16 @YOUNGSUPERMAN @NerdyHamster

Answer 2

http://akk.li/pics/anne.jpg
did this help

Answer 3

I would rather someone explain it to me instead of reading it in a link.

Answer 4

just look at the link bro

Answer 5

it will help

Answer 6

Can you just walk me through it instead? (:

Answer 7

no i helped u wiht the link thats all u need u can read

Answer 8

I'm looking for someone to actually help me first-hand, not send me links.

Answer 9

ok what ever bro

Answer 10

@kkbrookly are you there?

Answer 11

csc(x)=1/sin(x)

Answer 12

you can apply this identity and say sin(x)csc(x)=1 since sin(x)/sin(x)=1 on its domain of course

Answer 13

then it is all up to you to apply a pythagorean identity

Answer 14

I'm trying to look up a list of the Pythagorean identities so I can choose one, but I can't find them.

Answer 15

do you know sin^2(x)+cos^2(x)=1?

Answer 16

this is a pythagorean identity

Answer 17

you can write it a couple different ways
sin^2(x)=1-cos^2(x)
or
cos^2(x)=1-sin^2(x)

Answer 18

Yes, so I choose the one with sin right?

Answer 19

you have the left hand side is 1-sin^2(x) right?

Answer 20

when x isn't pi*n of course

Answer 21

if you want to be all crazy about it csc(x)=1/sin(x)
and so the domain of 1/sin(x) is all real numbers except when x is pi*n
you know where n is an integer
so \[\sin(x) \frac{1}{\sin(x)} =1 \text{ when } x \neq n \pi \\ \text{ and so we have } \sin(x) \csc(x)-\sin^2(x)=\cos^2(x) \text{ is an identity for number } \\ x \neq n \pi\]

Answer 22

That means it's an identity then

Answer 23

well an identity for all real numbers excluding when x is n pi
where n is an integer

if x is n pi where n is an integer then it isn't an identity at those times

Answer 24

That makes sense. Thank you so much! Can you help me with another one?

Answer 25

I actually have to go
sorry

Answer 26

That's alright! Thank you (: