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Unit Circle Calculator

Find the point (cos θ, sin θ) on the unit circle for any angle, with exact coordinates, quadrant, reference angle and all six functions.

Change the values and press Calculate to work out your own figures.

Enter an angle and choose degrees or radians.

About angle θIn the unit chosen below.
About angles inDegrees or radians.
Result
Point on the unit circle at 225°
(-0.7071067812, -0.7071067812)
Exact
(−√2/2, −√2/2)
tan(θ) = y ÷ x
1
Quadrant
III
Reference angle
45°

At 225° the unit circle point is (-0.7071067812, -0.7071067812).

All six functions
FunctionValueExact
sin(θ)-0.7071067812−√2/2
cos(θ)-0.7071067812−√2/2
tan(θ)11
csc(θ)-1.414213562−√2
sec(θ)-1.414213562−√2
cot(θ)11
Show the working
  1. x = cos θ, y = sin θ
  2. θ = 225° = 3.926990817 rad = 5π/4

How to use it

Enter an angle and choose degrees or radians.

Enter the values you know (decimals, fractions, surds such as 2√5, or angles such as π/3 in radians). Show the working gives the rule used at each step.

Key facts

(x, y) = (cos θ, sin θ); x² + y² = 1

Reading the circle

The point at angle θ from the positive x-axis has coordinates (cos θ, sin θ); its signs give the quadrant.

Questions

What is the point at 225°?

(−√2/2, −√2/2).

And at 5π/6?

(−√3/2, 1/2).

Formulas

(x, y) = (cos θ, sin θ); x² + y² = 1

Sources

Limitations

  • Angles can be typed in degrees or radians; radians may be written with π (π/3, 2pi/3).

Formula version 0.1.0Reviewed