Find all solutions to the equation.

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

(cosx + 1)^2 = 0

cosx = -1

that should help, no?

To find all the solutions to the equation cos^2(x) + 2cos(x) + 1 = 0, we can use a substitution to simplify the equation.

Let's substitute cos(x) with a new variable, let's say t.
So we have t^2 + 2t + 1 = 0.

Now, we can see that this equation is in the form of a quadratic equation, ax^2 + bx + c = 0, where a = 1, b = 2, and c = 1.

We can solve this quadratic equation by using the quadratic formula:
x = (-b ± √(b^2 - 4ac)) / (2a)

Applying this formula to our quadratic equation, we get:
t = ( -2 ± √(2^2 - 4*1*1) ) / (2*1)
t = ( -2 ± √(4 - 4) ) / 2
t = ( -2 ± √0 ) / 2

Since the discriminant (the part inside the square root) is equal to 0, there is only one solution for t.

t = -1

Now, we need to find the values of x that correspond to this value of t. We know that cos(x) = t, so using the inverse cosine function, we can find x.

x = arccos(-1)

The arccos(-1) represents the angle whose cosine is equal to -1.

The value of x that satisfies this equation is x = π.

Therefore, the solution to the equation cos^2(x) + 2cos(x) + 1 = 0 is x = π.