Question

Find the exact real value of arccos(1/2)

Answer 1

have you tried it yet? it's just like the one we did

Answer 2

cos=adj/hyp

Answer 3

cos=1/2

Answer 4

but i cant figure out the rest. im trying to see how arccos changes that or changes my answer

Answer 5

actually sorry, this is just a special value

Answer 6

not the same as the last :P
my bad

Answer 7

i thought so and plus the options dont match what i came up with.

Answer 8

like I said in the last post, what is the definition of the arccosine?

Answer 9

t=arccos(x) means what?

Answer 10

arccos(X)= cos(x)

Answer 11

no, the two functions are not the same... they are inverses

Answer 12

arccos(x)=t implies that cos(t)=x

Answer 13

so that means t is what kind of value?

Answer 14

oops. i dont know what t is, im confused.

Answer 15

t is for the triangle?

Answer 16

normally when we have \[\cos\theta=x\] what does \(\theta\) represent?

Answer 17

the theta is equal to the x or its just the value thats there

Answer 18

theta is *not* the x, x is the sine of theta

theta normally represents an *angle*, right?

Answer 19

yes that makes more since

Answer 20

so if\[\sin\theta=x\]and\[\sin^{-1}x=\theta\]then inverse trig functions are like asking "at what angle theta is the sine of that angle x?"

Answer 21

so in your case the question becomes "the cosine of what angle(s) is/are 1/2 ?"

Answer 22

i see so we have the hyp and the opp sides and we need the angle

Answer 23

no, in this case this should be a value you have memorized
the answer choices include pi unless they are in degrees, correct?

Answer 24

i think it is pi/6

Answer 25

so you are saying that cos(pi/6)=1/2 ?

Answer 26

the options are:
pi/3

2pi/3

-pi/6

pi/6

Answer 27

no its pi/3

Answer 28

correct :)

Answer 29

thanks