মান নির্ণয়
cos(45°+θ)cos(45°-θ)-sin(45°+θ)sin(45°-θ)=কত?
cos2θ
0
sin2θ
1
cos(45∘+θ)⋅cos(45∘−θ)−sin(45∘+θ)⋅sin(45∘−θ)=cos(45∘+θ+45∘−θ)=cos90∘=0 \begin{array}{l} \cos \left(45^{\circ}+\theta\right) \cdot \cos \left(45^{\circ}-\theta\right)-\sin \left(45^{\circ}+\theta\right) \cdot \sin \left(45^{\circ}-\theta\right) \\ =\cos \left(45^{\circ}+\theta+45^{\circ}-\theta\right) \\ =\cos 90^{\circ} \\ =0 \end{array} cos(45∘+θ)⋅cos(45∘−θ)−sin(45∘+θ)⋅sin(45∘−θ)=cos(45∘+θ+45∘−θ)=cos90∘=0
প্রমাণ কর যে, sin75∘+sin15∘sin75∘−sin15∘=3 \frac{\sin 75^{\circ}+\sin 15^{\circ}}{\sin 75^{\circ}-\sin 15^{\circ}}=\sqrt{3} sin75∘−sin15∘sin75∘+sin15∘=3.
tanθ=p হলে, cos2θ= কত? \tan \theta=p \text { হলে, } \cos 2 \theta=\text { কত? } tanθ=p হলে, cos2θ= কত?
যদি π2<θ<πএবংsinθ=35হয়, \frac{\pi}{2} < \theta < \pi এ ব ং \sin{\theta} = \frac{3}{5} হ য় , 2π<θ<πএবংsinθ=53হয়, তবে cosθ এর মান কত?
sin4x+cos4x \sin ^{4} x+\cos ^{4} x sin4x+cos4x -এর পর্যায় কত?
