এস ইউ আহাম্মদ স্যার

cos(45+θ)cos(45θ)sin(45+θ)sin(45θ)=\cos \left(45^{\circ}+\theta\right) \cos \left(45^{\circ}-\theta\right)-\sin \left(45^{\circ}+\theta\right) \sin \left(45^{\circ}-\theta\right)= কত ?

Loading answers...