Question

cos^2 x + 2 cos x + 1 = 0
Find all solutions in the interval [0, 2π).

HELP :(

Answer 1

Factor, then solve over interval

Answer 2

how do I do that!? D:
@Brittni0605

Answer 3

\[\cos ^{2}x + 2cosx+1=0\]

Answer 4

\[(cosx+1)(cosx+1)=0\]

Answer 5

\[cosx+1=0\]

Answer 6

\[cosx=-1\]

Answer 7

\[x=\cos^{-1}( -1)\]

Answer 8

\[x=\Pi \]

Answer 9

Is that answer taking into consideration the solution has to be in the interval of [0,2π)? @Brittni0605

Answer 10

Yes.