Question

find all solutions of cosx=0.8?

Answer 1

Mmmmm are we allowed to use a calculator? :d

Answer 2

sure lol

Answer 3

\[\Large \cos \color{green}{x}\quad=\quad \color{violet}{0.8}\]
We can rewrite this as the inverse cosine by swapping the argument of the function with the right side.\[\Large \cos^{-1}\color{violet}{0.8}\quad=\quad \color{green}{x}\]

Answer 4

There is a special button on most calculators for the inverse sine and cosine.

Answer 5

hummmmmmmmmmmm

Answer 6

You would probably want to be in `degree mode`

Answer 7

What type of calculator do you have? :o
If you can't figure it out, we could maybe just try using Google Calculator.

Answer 8

can u give it to me ??

Answer 9

I have casio

Answer 10

Does it have a \(\Large cos^{-1}\) button?

Answer 11

yes is dose

Answer 12

oh goodie :O

Answer 13

??

Answer 14

What calculator is it D: Maybe I can guide you through it..
Casio what?

Answer 15

hummmmmmmm it is fx-115es

Answer 16

??

Answer 17

Mmmm ok so how do you get the cos^-1 to show up?
I think you press the `shift` button, then press the cosine button, yes?

Answer 18

hummm shift & cos

Answer 19

??

Answer 20

cos is positive in quadrants 1 and 4.
cosx.8 = 36.86989765deg +360n where n is an integer
and cosx.8 also = 323.1301024deg +360n where n is an integer

Answer 21

oh that is the full answer ? I just have to type it like that and that is it ?

Answer 22

make sure your answer is in rads or degrees, what ever it calls for, that is in degrees.

Answer 23

Make sure you round to the appropriate number of decimals

Answer 24

how to do that ? :(

Answer 25

does it tell you to round your answers to a certain number of decimals?
does it tell you to give an answer in exact form or decimal form?

Answer 26

yes it dose

Answer 27

follow the directions

Answer 28

where ?

Answer 29

Cos x = 0.8
So, x = 37 or (360-37)

Answer 30

How ever your teacher or homework tells you to represent the answer, follow those directions

Answer 31

omg im so confused :(

Answer 32

How does your directions tell you to present an answer?

Answer 33

he just said Find all solutions of cos x=0.8

Answer 34

?