JEE Advanced
- Exam
- JEE Advanced
- Subject
- Mathematics
- Chapter
- Trigonometry
JEE Advanced · Mathematics · Trigonometry
If 4+ 8- 32+ 768 =a 2 ((11 π)/(b)), where a and b are natural...
If a and are natural numbers then \frac{b}{a} is divisible by
Options
- A2
- B4
- C3
- D6
Correct answer
D. 6
Step-by-step solution
\text { So } \sqrt{4+\sqrt{8-\sqrt{32+32 \cos \frac{\pi}{6}}}}=\sqrt{4+\sqrt{8-8 \cos \frac{\pi}{12}}}=\sqrt{4+4 \sin \frac{\pi}{24}}=\sqrt{4+4 \cos \frac{11 \pi}{24}}=\sqrt{4\left(1+\cos \frac{11 \pi}{24}\right)}=\sqrt{4.2 \cos ^2 \frac{11 \pi}{48}}=2 \sqrt{2} \cos \frac{11 \pi}{48}\mathrm{a}=2, \mathrm{~b}=48\therefore \frac{\mathrm{b}}{\mathrm{a}}=24$