Question

evaluate cos^-1( 1/2)

Answer 1

let \(\large cos^{-1}\frac{1}{2}=y \)
so \(\large \frac{1}{2}=cosy \)

cosine of what angle, y, is 1/2 ?

Answer 2

pi/8?

Answer 3

no...
the answerS are common angles...
look at your unit circle...

Answer 4

here's a unit circle, page 3:
http://tutorial.math.lamar.edu/pdf/Trig_Cheat_Sheet.pdf

Answer 5

its in 60 degrees and 300 degrees

Answer 6

correct...

Answer 7

thats the answer?

Answer 8

yes...
but actually only 60 degrees (or pi/3) is the principle answer.

Answer 9

oh okay thank you!

Answer 10

yw...:)