Find the point on the unit circle for any angle, with its sine, cosine, tangent, and quadrant. Enter the angle and unit.
Usage Tip
Memorize the first quadrant and use symmetry: every other angle mirrors a first-quadrant value with a sign change.
x is the cosine, y is the sine, tan = y ÷ x
It is the foundation for defining trig functions at any angle.
The x-coordinate is the cosine; the y-coordinate is the sine.
Tangent is undefined where the cosine is zero (90 and 270 degrees).
The unit circle is a circle of radius one centered at the origin. For any angle, the point where its terminal side meets the circle has an x coordinate equal to the cosine and a y coordinate equal to the sine, and the tangent is sine divided by cosine.
The signs of these values depend on the quadrant: sine is positive in the first and second quadrants, cosine in the first and fourth, and tangent in the first and third. Angles beyond 360 degrees simply wrap around, and tangent is undefined at 90 and 270 degrees where the cosine is zero.