Use a double-angle formula to rewrite the expression. 10 cos²x - 5 A)5 cos x B)cos 5x C)10 cos 2x D)10 cos x E)5 cos 2x

Name: Use a double-angle formula to rewrite the expression. 10 cos 2 x - 5 A)5 cos x B)cos 5x C)10 cos 2x D)10 cos x E)5 cos 2x
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Question

Quizplus · Accepted Answer

The expression can be rewritten using the double-angle formula for cosine, which is $cos(2x) = 2cos^2(x) - 1$. Given the expression $10cos^2(x) - 5$, it can be rewritten as $5(2cos^2(x) - 1)$, which simplifies to $5 cos(2x)$ using the double-angle formula.

Use a Double-Angle Formula to Rewrite the Expression