pre-calc help !!!!!!!

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cos^2x-sin^2 x+1=cos x

• pre-calc help !!!!!!! -

sin^2 x = 1 - cos^2 x

so we have
cos^2 x - 1 + cos^2 x + 1
or
2 cos^2 x
on the left
so

2 cos^2 x = cos x

cos x = 1/2

x = 60 degrees or pi/3 radians
or
300 degrees or 5 pi/3 radians

• pre-calc help !!!!!!! -

from Damon's middle section:

2cos^2 x - cosx = 0
cosx(2cosx - 1) = 0
cosx = 0 or cosx = 1/2
so from cosx=1/2 we have the 2 answers that Damon gave

from cosx = 0 , we also have
x = 90° or x = 270°
x = π/2 or x = 3π/2

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