Question

how do I find sin 5ᴨ/8, cos 5ᴨ/8 and tan 5ᴨ/8 using trig identities

Answer 1

What is ᴨ

Answer 2

use formula for sin4x

Answer 3

the problem doesn't say...just says to use trigonometric identities to find the values

Answer 4

But what is "ᴨ" is it theta or something else. What is it?

Answer 5

expand sin4x, put x as 5pi/8 and equate the expa nsion of sin4x to 1

Answer 6

Is it pi?

Answer 7

yes

Answer 8

Sin ((270-45)/2)=sin (5(pi)/8)

Answer 9

Do you understand this step?

Answer 10

Do you understand the step "Sin ((270-45)/2)=sin (5(pi)/8)"

Answer 11

not really, but i think you got the 270 from 3pi/2 and the 45 from pi/4....

Answer 12

Well, I am trying to express the thing in degree format. (Sorry for using jumbled form). By the term I mean 180 degree

Answer 13

By the term pi mean 180 degree

Answer 14

\[Sin ((3\pi/2-\pi/4)/2)=sin (5\pi/8)\]

Answer 15

Now does that makes sense?

Answer 16

yes

Answer 17

*make

Answer 18

Now can you do the rest, or I will have to show you every steps.

Answer 19

so, sin (225/2)=sin (112.5)?
you might have to show me the steps.

Answer 20

or is it sin (5pi/4 divided by 2)

Answer 21

Yes, thats true, but thats not helpful here.
\[Sin ((3\pi/2-\pi/4)/2)=sin (5\pi/8)\]
\[=>sin (5\pi/8)=\sqrt(0.5(1-cos(3\pi/2-\pi/4))\]

Answer 22

Now you got to use addition formula for cos to solve the part with cos, and then it will be done

Answer 23

I am totally lost .....this does not look at all familiar.....

Answer 24

are you familiar with double angle formula for trig?

Answer 25

i'm sure we went over them....but nothing coming to mind

Answer 26

Then you can't expect to get this thing within your understandability range

Answer 27

that's why I am having trouble....thought if someone walked me through it, it would make sense

Answer 28

If you wish I can tutor you (in exchange of some nominal payment) :)

Answer 29

Seems like you are not interested. So may I leave?

Answer 30

didn't know i had to pay for help

Answer 31

No no not that

Answer 32

you can get free help here for ever

Answer 33

But I don't think they will be very helpful

Answer 34

So incase you need personal help

Answer 35

I mean through audio chatting and virtual black board

Answer 36

I can't teach you everything here. This place is too inconvenient to type even a simple equation

Answer 37

I mean no one can

Answer 38

thanks for the offer, but rather just stay here

Answer 39

Thats great. No problem