Match the x-coordinates with their corresponding pairs of y-coordinates on the unit circle.

y = + - square root 5 over 3

y = + - square root 7 over 3

y = + - 3 over 3

y = + - 2 square root 2 over 2

y = + - square root 5 over 3

y^2 + x^2 = 1 = > x^2 = 1 - y^2 = 1 - 5/9 = 4/9 = > x = + / - 2/3

Answer: x = + / - 2/3

y = + - square root 7 over 3

y^2 + x^2 = 1 = > x^2 = 1 - y^2 = 1 - 7/9 = 2/9 = > x = + / - (√2) / 3

Answer: x = + / - (√2) / 3

y = + - 3 over 3

x^2 = 1 - y^2 = 1 - 3/9 = 1 - 1/3 = 2/3 = > x = + / - (√2/3)

Answer: x = + / - √ (2/3)

y = + - 2 square root 2 over 2

= y = + / - 2 (√2) / 2 = √2 ... these y-coordinates are out of the unit circle, then there is not a corresponding x - coordinate for them.