1. \(\cfrac{1-sin^2⁡ 30°}{1+sin^2⁡ 45°} \) \(\times \cfrac{cos^2⁡ 60° + cos^2⁡ 30°}{cosec^2⁡ 90° -cot^2⁡ 90°} \div (sin 60° tan 30°)\)

2. মান নির্ণয় করো:
\(\cfrac{1-sin^2⁡ 30°}{1+sin^2⁡ 45°} × \cfrac{cos^2⁡ 60°+cos^2⁡ 30°}{cosec^2 90°-cot^2⁡ 90°}\) \( ÷(sin 60°.tan 30°)\)

3. মান নির্ণয় করো:
\(\cfrac{1-\sin^2 30°}{1+\sin^2 45°}\times \cfrac{\cos^2 60°+\cos^2 30°}{cosec^2 90°-\cot^2 90°}\) \(\div (\sin 60° \tan 30°)\) Madhyamik 2007

4. \(\cfrac{1-sin^260°}{1+sin^245°} \times \cfrac{cos^260°+cos^230°}{cosec^290°-cot^290°}\)\(+sin60°.tan^230°\) = ?

(a) \(\sqrt3\) (b) \(\cfrac{\sqrt3}{6}\) (c) \(\cfrac{1}{6}\) (d) \(\cfrac{\sqrt3+1}{6}\)