Question

Solve on the interval [0, 2Pi):
1 + cos(theta) = (sqrt(3)+2)/2
A. Pi/6 , 5Pi/6
B. Pi/3 , 5Pi/3
C.Pi/6 , 11Pi/6
D. 7Pi/6, 11Pi/6
Please answer with explanation.

Answer 1

it is the same as cos(theta)=sqrt(3)/2

Answer 2

got it?

Answer 3

eh yeah i suppose ...why is it that ...what about the 1 and the 2? ...eh...\[(\sqrt{3} + 2) \div 2\]

Answer 4

@hartnn

Answer 5

cos(theta)=(sqrt(3)+2)/2 -1=sqrt(3)+2/2 - 2/2

Answer 6

((3√+2)÷2) -1
not 2 -1

Answer 7

\[\frac{ \sqrt{3}+2 }{ 2 }-1?\]

Answer 8

thats what it would be

Answer 9

\[\frac{ \sqrt{3} }{ 2 } +\frac{ 2 }{ 2 } -1\]
\[\frac{ \sqrt{3} }{ 2 } +1 -1\]
cos(theta) =√3 /2

Answer 10

then what do i do? ..i understand that ty nu

Answer 11

\[\theta = \cos^{-1} \frac{ \sqrt{3} }{ 2 }\]

Answer 12

as theta value would be positive means it lies in the 1st and 4th quadrant bcos in these quadrants value of cos is positive.

Answer 13

then solve for \[\cos( \theta )=\frac{ \sqrt{3} }{ 2 }\]

Answer 14

wait ...can you reexplain how you moved cosine over?

Answer 15

well its simple.. when u move cosine or any trignometric on other side of equal u have to inverse it.. do not mistake it for power ^-1 it is the inverse function.. u can find in calculator if u r allowed to use it.

Answer 16

it's arccosin, not cosin

Answer 17

arccosin is the inverse of cosin

Answer 18

inverse function ?

Answer 19

yes i think that's what is called.. they are also named as "arc" functions.

Answer 20

sin^-1?

thats 2nd sin button

Answer 21

hmm yes maybe, it differs from calculator to calculator.. you have to find for cos^-1 on ur calculator and find the value can u tell me what u have got?

Answer 22

be careful, there are some default setting in your calculator that it would not return all the results you want.

Answer 23

it looks just like that ....and it depends on radians and degrees and stuff?
if i put cos^-1 without anything it would be an error ..i need a value to put in it

Answer 24

hmm by defualt it give in degree but u can change settings to get answer in radians.. and to find value do like this
cos^-1 (√3/2) .. i think this will give u the value 30 degree.

Answer 25

be careful of your interval. @Mpost1994

Answer 26

yes and after that? eh..how do i get the answer?

Answer 27

hmm just press equal sing on ur calculator u should get soem answer.

Answer 28

no i meant for the question

Answer 29

ohh sorry.. well u do u will get 30 or pi/6 in radians.
as the value is positive . u have to see where cos function is positive .. it is in 1st Quadrant and 4th
so ,
1st quad = pi/6
4th quad = 2pi - pi/6

Answer 30

11pi/6?

Answer 31

yes.

Answer 32

ok ty :3

Answer 33

yw :)