Question

Find the exact value of cos-1the quantity square root of three divided by two.

Answer 1

\[\cos^{-1} (\sqrt{3}/2)\]

Answer 2

we take inverse of ratio to find an angle so you need an angle when cos theta = sqrt{3}/2
1st) you can use unit circle
2nd) calculator
3rd) familiar with 30-6-90 /45-45-90 triangle theorem

Answer 3

btw in the order pair (x,y)
cos = x
sin = y

Answer 4

so what do i do next

Answer 5

1st) you can use unit circle
2nd) calculator
3rd) familiar with 30-6-90 /45-45-90 triangle theorem
3 ways to find an answer pick one :=)

Answer 6

it's 30-60-90 ****

Answer 7

unit circle i guess

Answer 8

alright
at what angle cos = sqrt{3}/2

Answer 9

30 and 60

Answer 10

no just 30

Answer 11

there should be two angle when cos =sqrt{3}/2 remember it's reflected over they axis

Answer 12

the*

Answer 13

i thought you only needed one but okay then 330

Answer 14

well there are two
you should write both as an ansaawer just in case if they are looking for more than one value hmm

Answer 15

okay so whats the next step?

Answer 16

that's it

Answer 17

is there any statement about degree or radian ? i mean answer should be in degree or radian ?

Answer 18

but its the arc cosine

Answer 19

its a radian

Answer 20

right when we need an angle we take invs of ratio
so that's why it's arccos

Answer 21

ohh okay formula to convert degree to radian \[\huge\rm rad=\frac{ \pi}{ 180} \times degree \]

Answer 22

well which angle do i use

Answer 23

both angles
30 and 330

Answer 24

cant i just use the radian it has on the unit circle next to it

Answer 25

yes you can

Answer 26

you will get the same answer

Answer 27

but both are an answer choice

Answer 28

which one is right

Answer 29

ohh so you can pick only one ?

Answer 30

yes

Answer 31

i'll pick 30 bec that's the angle where it starts

Answer 32

330 is areflection

Answer 33

so pi/6?

Answer 34

looks good

Answer 35

thank you

Answer 36

yw