sin 70∘cos 20∘+sin 59∘cos 31∘−8 sin2 30∘=____

1.	sin 70∘cos 20∘+sin 59∘cos 31∘−8 sin2 30∘=____
Answer» $\frac{s i n 70^{\circ}}{c o s 20^{\circ}} + \frac{s i n 59^{\circ}}{c o s 31^{\circ}} - 8 s i n^{2} 30^{\circ} =$ ____

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