Trigonometry - Principal values of inverse trigonometric functions

1.  X 0 $1 \over 2$ $\sqrt {2} \over 2$ $\sqrt {3} \over 2$ 1 $arcsin \,x$ $0^0$ $30^0$ $45^0$ $60^0$ $90^0$ $arccos \,x$ $90^0$ $60^0$ $45^0$ $30^0$ $0^0$ x $-{1 \over 2}$ $-{\sqrt {2} \over 2}$ $-{\sqrt {3} \over 2}$ $-1$ $arcsin \,x$ $-30^0$ $-45^0$ $-60^0$ $-90^0$ $arccos \,x$ $120^0$ $135^0$ $150^0$ $180^0$
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2.  x 0 $\sqrt 3 \over 3$ 1 $\sqrt 3$ $-{\sqrt 3 \over 3}$ -1 $- \,\sqrt 3$ arctan x $0^0$ $30^0$ $45^0$ $60^0$ $-30^0$ $-45^0$ $-60^0$ arccot x $90^0$ $60^0$ $45^0$ $30^0$ $120^0$ $135^0$ $150^0$