প্রশ্ন: যদি A = 30° হয়, তবে 2tanA/(1 - tan²A) = কত?

সমাধান:
2tanA/(1 - tan²A)
= 2tan30°/{1 - {tan30°)²}
= {2.(1/√3)} / {1 - (1/√3)²}
= (2/√3) / {1 - (1/3)}
= (2/√3) / (2/3)
= (2/√3) × (3/2)
= √3