SOLUTION: Solve 10cosx^2-12cosx-7=0. Use degrees and round your answer to the nearest hundredth.

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Question 769869: Solve 10cosx^2-12cosx-7=0. Use degrees and round your answer to the nearest hundredth.
Answer by lwsshak3(11628) About Me  (Show Source):
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Solve 10cosx^2-12cosx-7=0. Use degrees and round your answer to the nearest hundredth.
10cos^2x-12cosx-7=0
use quadratic formula to solve for cosx
cosx+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
a=10, b=-12, c=-7
Ans:
cosx=1.629 (reject, -1 < cosx < 1)
or
cosx=-0.430