\(sin(\theta-30^o)=\cfrac{1}{2}\) হলে \(cos \theta\) এর মান _____
Madhyamik 2024
\(sin(\theta-30^o)=\cfrac{1}{2}\) হলে \(cos \theta\) এর মান \(\cfrac{1}{2}\)
\(sin(\theta-30^o)=sin 30^o\)
বা, \(\theta-30^o=30^o\)
বা, \(\theta=30^o+30^0=60^o\)
\(\therefore cos \theta=cos 60^o=\cfrac{1}{2}\)