যদি A = 30° হয় তবে (1 - tan²A)/(1 + tan²A) = কত?

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

সমাধান:
দেওয়া আছে,
A = 30°

এখন,
(1 - tan²A)/(1 + tan²A)
= {1 - (tan30°)²}/{1 + (tan30°)²}
= {1 - (1/√3)²}/{1 + (1/√3)²}
= {1 - (1/3)}/{1 + (1/3)}
= (2/3)/(4/3)
= (2/3)/(3/4)
= 1/2