Use an Identity to Write the Expression as a Single $2 \cos ^ { 2 } 4 x - 1$

question 491

Multiple Choice

Use an identity to write the expression as a single trigonometric function or as a single number.
- $2 \cos ^ { 2 } 4 x - 1$

• A) \(\cos 4 x\)
• B) \(2 \sin 4 x\)
• C) \(\frac { 1 } { 2 } \sin 16 x\)
• D) \(\cos 8 x\)