Find the Derivative of F(x)= Sin (7x)· Sin (8x) $7 \cos ( 8 x ) \sin ( 7 x ) - 8 \cos ( 7 x ) \sin ( 8 x )$

question 90

Multiple Choice

Find the derivative of f(x) = sin (7x) · sin (8x) .

• A) \(7 \cos ( 8 x ) \sin ( 7 x ) - 8 \cos ( 7 x ) \sin ( 8 x )\)
• B) \(7 \cos ( 8 x ) \sin ( 7 x ) + 8 \cos ( 7 x ) \sin ( 8 x )\)
• C) \(8 \cos ( 8 x ) \sin ( 7 x ) - 7 \cos ( 7 x ) \sin ( 8 x )\)
• D) \(8 \cos ( 8 x ) \sin ( 7 x ) + 7 \cos ( 7 x ) \sin ( 8 x )\)

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