document.write( "Question 962699: Solve the following equation on the interval [0, 2pi]
\n" ); document.write( "cos^2 x + 2 cos x + 1 = 0 \n" ); document.write( "

Algebra.Com's Answer #588192 by josgarithmetic(39617) $\"\"$ $\"About$

You can put this solution on YOUR website!
The left side expression is a perfect square trinomial, and therefor factorable, so you can finally use Zero Product Rule. \n" ); document.write( "

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