Arc-ed起来

几何

$\large \arcsin 1 + arccos 1 + arctan 1 + text{arccot} \，1 + text{arcsec} \，1 + text{arcccsc} \，1 = \ ?$

0

\ dfrac{\π}{4}

\ dfrac{\π}{2}

3 \ \ dfrac{π}{4}

\π

5 \ \ dfrac{π}{4}

3 \ \ dfrac{π}{2}

7 \ \ dfrac{π}{4}