Find all solutions to the equation.

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

Question

Find all solutions to the equation.

cos^2x + 2 (cos x) + 1 = 0

anonymous · Answer

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

anonymous · Answer

@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 $$2,\pi$$

campbell_st · Answer

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