Question

Which of the following could be points in the unit circle A. (6/7, srqt13/7) B. (5/13, 12/13) C. (4/3, 4/5) D. (1/3, 2/3)

Answer 1

A and B

Trust me folk

Answer 2

recall that a Unit Circle is called that because its radius is just 1.

now, using the pythagorean theorem, c = √( a² + b²) whatever the values for "a" and "b" in the (a,b) point, they must yield a value c = 1, a radius of 1.

`\bf \boxed{A}~\hspace{5em}c=\sqrt{\left( (6)/(7) \right)^2+\left( (√(13))/(7) \right)^2}\implies c=\sqrt{(36)/(49)+(13)/(49)}\implies c=\sqrt{(49)/(49)} \\\\\\ ~\hspace{7em}c=√(1)\implies c=1~~\textit{\Large \checkmark} \\\\\\ \boxed{B}~\hspace{5em}c=\sqrt{\left( (5)/(13) \right)^2+\left( (12)/(13) \right)^2}\implies c=\sqrt{(25)/(169)+(144)/(169)}\implies c=\sqrt{(169)/(169)} \\\\\\ ~\hspace{7em}c=√(1)\implies c=1~~\textit{\Large \checkmark}`