Suppose that (x,5/13) is a point in quadrant 2 lying on the unit circle. Find x. Write the exact value, not a decimal approximation.

Answer 1

x is negative in Q 2

(n/13)^2 + (5/13)^2^2 = (13/13)^2

12=n
so
x = 12/13

Answer 2

or, in QII, x = -12/13