Question

Refer to the graph of
y = sin x or y = cos x
to find the exact values of x in the interval [0, 4π] that satisfy the equation for 2cos x = −2

Answer 1

\[2\cos(x)=-1\iff \cos(x)=-1\]

Answer 2

cosine is \(-1\) at \(x=\pi, 3\pi,5\pi,...\)

Answer 3

It says that is not right... Which is why I am confused.

Answer 4

in the interval \([0,4\pi]\) the two answers are \(\pi\) and \(3\pi\)

Answer 5

oh ok that makes sense. Yes that is right then.

Answer 6

whew

Answer 7

I appreciate it thanks.