Question

help please !! solve the equation on the interval
[ 0, 2pi )

Answer 1

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

this is a quadratic equation and factors to

(cos x + 1)^2 = 0

Answer 2

then whats the next step

Answer 3

@directrix

Answer 4

subtract both sides by 2

Answer 5

1*

Answer 6

im confused

Answer 7

@welshfella told you (cos x + 1)^2 = 0. so you are going to then subtract both sides by 1 to get cos x by it'self

Answer 8

So, you'll get the answer cos x = -1 and cos x = -1 because writing (cos x + 1)^2 is the same thing as (cos x +1)(cosx +1)

Answer 9

so then cos (x) = -1

Answer 10

and that'll be pi ?

Answer 11

yes, that's correct