Question

Find all solutions to the equation.

cos^2x + 2 (cos x) + 1 = 0

Answer 1

\[\cos^2x+ 2(cosx)+1=0\]

Answer 2

@campbell_st mind helping me with this one? It's basically the same question as my last one but not solving by the interval of \[2,\pi\]

Answer 3

ok... so you are asked to find the general solution

if you have

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

and in the previous solution and as you habe shown here

\[x = \pi\]

the general solution for an undefined domain is

\[x = \pm \cos^{-1}(-1) + 2n \pi\]

where n is an integer

because of the periodic nature of the cos curve, the solution will repeat every 2pi

hope it makes sense