Use a graphing utility to graph y1 and y2 in the interval [−2𝜋, 2𝜋]. Use the graphs to find real numbers x such that

Question

y1 = y2.
(Enter your answers as a comma-separated list.)
y1 = cos x
y2 = 1

Is the answer 𝜋 ,-𝜋 ? or is it zero? Because I don't see the lines intersecting within the interval [−2𝜋, 2𝜋]. Or am I just looking at the question incorrectly?

Answer 1

Wait can some one confirm if its -2π, 0, 2π?

Answer 2

Never mind I figured it out :)

Answer 3

the cosine of 0º (0 rad) is 1 ... that should be in the middle of the interval

-2π and 2π are the same location on the unit circle as zero
... are the ends of the interval included?

look at the cosine curve