[tex]\dfrac{5 \sin 87^{\circ} + \tan 72^{\circ} - \sec 5^{\circ}}{\cot 18^{\circ}-\csc 85^{\circ}+5\cos 3^{\circ}}\\\\\\=\dfrac{5\sin\left(90^{\circ}-3^{\circ} \right) + \tan\left(90^{\circ}-18^{\circ} \right)-\sec\left(90^{\circ}-85^{\circ} \right)}{\cot 18^{\circ}-\csc 85^{\circ}+5\cos 3^{\circ}}\\\\\\=\dfrac{5\cos 3^{\circ} + \cot 18^{\circ}-\csc 85^{\circ}}{\cot 18^{\circ}-\csc 85^{\circ}+5\cos 3^{\circ}}\\\\\\=1[/tex]
