I have the answers, so I don't need these solved I just need to know how they got the answers because the book doesn't explain it clearly.

Give exact real number value of y
1. y = sin^-1 0

2. y = arctan (squareroot 3/3)

find exact value

3.cos [arcsin(-1/2)]

solve for all values in the interval [0,2pi)

4. 2 sin angle + squareroot 3 = 0

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