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ratelena [41]
2 years ago
9

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

Mathematics
1 answer:
Schach [20]2 years ago
4 0

x= \pi

Step-by-step explanation:

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

Let u= \cos x

Then u^2+2u+1=(u+1)^2=0

or

\cos x = -1

This gives us x= \pi or all integer multiples of \pi (n \pi)

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