Question

Given angle x, where 0 <= x < 360 (degrees), cos(x) is equal to a unique value.
Determine the value of to the nearest degree. Justify your answer.

Answer 1

either 1 or -1 is attained only once on the given domain.

Answer 2

Steve - Could you elaborate on your answer please? I don't understand where you got those two numbers from

Answer 3

cos(x) assumes all values between -1 and 1. Each of those values appears twice in a period of the curve. Since you want a unique value,

x = 0 so cos(x) = 1
or
x = 180, so cos(x) = -1

for any other value where cos(x) = k,
cos(360-x) is also equal to k.

Look at the graph and you will see what I mean.