Question

The value of the definite integral $\underset{0}{\overset{\pi /2}{\int }}\left({\cos }^{10}x\cdot \sin 12x\right)dx$, is equal to

• A. $\frac{1}{10}$
• B. $\frac{1}{11}$
• C. $\frac{1}{12}$
• D. $\frac{1}{22}$

Answer 1

Answer: (B)

$\underset{0}{\overset{\pi /2}{\int }}\left({\cos }^{10}x\cdot \sin (11x+x)\right)dx$ expand and use by parts.