Evaluate the Indefinite Integral $\int x \cos 9 x d x$

question 62

Multiple Choice

Evaluate the indefinite integral. $\int x \cos 9 x d x$

• A) \(\frac{1}{81} \sin 9 x+\frac{x}{9} \cos 9 x+C\)
• B) \(\frac{1}{81} \cos 9 x+\frac{x}{9} \sin 9 x+C\)
• C) \(\frac{1}{9} \cos 9 x+\frac{x}{9} \sin 9 x+C\)
• D) \(\frac{x}{81} \cos 9 x+\frac{x}{9} \sin 9 x+C\)
• E) \(\text { None of these }\)

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