Evaluate the Integral $$\int \cos 7 x \cos 3 x d x$$

question 13

Multiple Choice

Evaluate the integral.
- $$\int \cos 7 x \cos 3 x d x$$

• A) \(\frac { 1 } { 8 } \sin 4 x - \frac { 1 } { 20 } \sin 10 x + C\)
• B) \(\frac { 1 } { 8 } \cos 4 x + \frac { 1 } { 20 } \cos 10 x + C\)
• C) \(\frac { 1 } { 8 } \sin 7 x + \frac { 1 } { 20 } \sin 3 x + C\)
• D) \(\frac { 1 } { 8 } \sin 4 x + \frac { 1 } { 20 } \sin 10 x + C\)