The point P is on the unit circle. Find P(x, y) from the given information. The x-coordinate of P is − 1/4 , and P lies above the x-axis.

Answer 1

If P lies above the X-axis, it follows that the Y coordinate is positive. If P lies on the unit circle (radius = 1), then we can construct a right triangle with the following coordinates: x = -1/4 and y = ? > 0.

Using pythagorean theorem, x² + y² = r²--> (-1/4)² + y² = 1² = 1. or y = sqrt (1 - (-1/4)²) = sqrt(1 - 1/16) = sqrt(16/16 - 1/16)

= sqrt(15/16) or sqrt(15)/4.