# pre cal 2

solve the equation 4cos^2x-1=0

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1. 4c0s^2x - 1 = 0.
4cos^2x = 1,
Divide both sids by 4:
cos^2x = 0.25,
Take sqrt of both sides:
cosx = 0.5,
X = 60 deg.

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posted by Henry

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