প্রদত্ত রাশি,
$\frac{1-cos^260^\circ}{1+cos^260^\circ}+sec^260^\circ$
$=\frac{1-\left(\frac{1}{\sqrt3}\right)^2}{1+\left(\frac{1}{\sqrt3}\right)^2}$
$=\frac{1-\frac{1}{3}}{1+\frac{1}{3}}$
$=\frac{\frac{3-1}{3}}{\frac{3+1}{3}}$
$=\frac{\frac{2}{3}}{\frac{4}{3}}$
$=\frac{2}{3} \times \frac{3}{4}$
$=\frac{1}{2}$
$\therefore$ নির্ণেয় মান $\frac{1}{2}$