How do you use a double-angle formula to rewrite the expression $6 {cos}^{2} x - 3$ $6 cos^2x-3$ ?

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Answer 1 · 2015-04-26T01:21:01

$Double Angle Formula: cos (2 x) = 2 {cos}^{2} (x) - 1$ $"Double Angle Formula: "cos(2x) = 2cos^2(x)-1$

$6 {cos}^{2} (x) - 3 = 3 (2 {cos}^{2} (x) - 1)$ $6 cos^2(x) -3 = 3(2cos^2(x)-1)$

$= 3 cos (2 x)$ $=3cos(2x)$

How do you use a double-angle formula to rewrite the expression 6 cos^2x-36cos2x−36 cos^2x-3?