4(sin⁻¹(1/√5) + cot⁻¹3) = কত?

ব্যাখ্যা

4(sin⁻¹(1/√5) + cot⁻¹3) = 4(tan⁻¹(1/2) + tan⁻¹(1/3)) = 4·tan⁻¹{(1/2 + 1/3)/(1 − (1/2)(1/3))} = 4·tan⁻¹1 = 4×π/4 = π