The unit-circle identity recovers the magnitude of a missing coordinate, but squaring erases its sign. Solve for the squared coordinate, take both algebraic roots, and then use the quadrant to keep the geometrically valid sign. Substituting both coordinates back into the identity provides a clean check.
Inside Gozunta
Turn the preview into practice.
More than a preview
Gozunta lets you study this problem—and more than 10,000 others.
Create targeted learning sessions, use hints, check your answer, read the walkthrough, watch the video, print the work, and track your progress.
