যদি \(sinθ−cosθ=0,\) \( (0°<θ<90°)\) এবং \(secθ+cosecθ=x\), হয় তাহলে \(x\) এর মান — (a) \(1\) (b) \(2\) (c) \(\sqrt2\) (d) \(2\sqrt2\)
Madhyamik 2020
Answer: D
\(sinθ−cosθ=0\)
বা, \(sinθ=cosθ=sin(90°-\theta)\)
বা, \(\theta=90°-\theta\)
বা, \(2\theta=90°\)
বা, \(\theta=45°\)
\(secθ+cosecθ=x\)
\(\therefore x=sec45°+cosec45°=\sqrt2+\sqrt2\)
\(=2\sqrt2\)