Calculate cos(1)
cos is found using Adjacent/Hypotenuse
Determine quadrant:
Since 0 ≤ 1 ≤ 90 degrees
it is in Quadrant I
sin, cos and tan are positive.
Determine angle type:
1 < 90°, so it is acute
cos(1) = 0.99984769515674
Write cos(1) in terms of sin
Since 1° is less than 90...
We can express this as a cofunction
cos(θ) = sin(90 - θ)
cos(1) = sin(90 - 1)
cos(1) = sin(89)
Special Angle Values
| θ° | θrad | sin(θ) | cos(θ) | tan(θ) | csc(θ) | sec(θ) | cot(θ) |
|---|---|---|---|---|---|---|---|
| 0° | 0 | 0 | 1 | 0 | 0 | 1 | 0 |
| 30° | π/6 | 1/2 | √3/2 | √3/3 | 2 | 2√3/3 | √3 |
| 45° | π/4 | √2/2 | √2/2 | 1 | √2 | √2 | 1 |
| 60° | π/3 | √3/2 | 1/2 | √3 | 2√3/3 | 2 | √3/3 |
| 90° | π/2 | 1 | 0 | N/A | 1 | 0 | N/A |
| 120° | 2π/3 | √3/2 | -1/2 | -√3 | 2√3/3 | -2 | -√3/3 |
| 135° | 3π/4 | √2/2 | -√2/2 | -1 | √2 | -√2 | -1 |
| 150° | 5π/6 | 1/2 | -√3/2 | -√3/3 | 2 | -2√3/3 | -√3 |
| 180° | π | 0 | -1 | 0 | 0 | -1 | N/A |
| 210° | 7π/6 | -1/2 | -√3/2 | √3/3 | -2 | -2√3/3 | √3 |
| 225° | 5π/4 | -√2/2 | -√2/2 | 1 | -√2 | -√2 | 1 |
| 240° | 4π/3 | -√3/2 | -1/2 | √3 | -2√3/3 | -2 | √3/3 |
| 270° | 3π/2 | -1 | 0 | N/A | -1 | 0 | N/A |
| 300° | 5π/3 | -√3/2 | 1/2 | -√3 | -2√3/3 | 2 | -√3/3 |
| 315° | 7π/4 | -√2/2 | √2/2 | -1 | -√2 | √2 | -1 |
| 330° | 11π/6 | -1/2 | √3/2 | -√3/3 | -2 | 2√3/3 | -√3 |
Show Unit Circle
Final Answer
cos(1) = 0.99984769515674
