cos(315°) = 0.70710678, exactly √2/2.
cos(315°) = 0.70710678, exactly √2/2. The angle 315° equals 7π/4 radians (315 × π/180).
Exact form: √2/2. Decimal: 0.70710678 (rounded to 8 places).
315° lies quadrant IV. Remember that cosine is positive in quadrants I and IV, and negative in the others, which decides the sign of the answer.
If you get a different number, the calculator is probably in RAD mode. In radians you would enter 7π/4 instead of 315.
| sin 315° | = -0.70710678 |
| cos 315° | = 0.70710678 |
| tan 315° | = -1 |
| Angle | Radians | Cos |
|---|---|---|
| 0° | 0 | 1 |
| 30° | π/6 | 0.866025 |
| 45° | π/4 | 0.707107 |
| 60° | π/3 | 0.5 |
| 90° | π/2 | 0 |
| 120° | 2π/3 | -0.5 |
| 135° | 3π/4 | -0.707107 |
| 150° | 5π/6 | -0.866025 |
| 180° | π | -1 |
| 270° | 3π/2 | 0 |
| 360° | 2π | 1 |
cos(315°) = 0.70710678, exactly √2/2.
315° = 7π/4 radians, so cos(315°) = cos(7π/4) = 0.70710678.
It is most likely set to radians. Switch to degree (DEG) mode before entering the angle.
Positive.
Yes. Use the calculator on this page, or open the full free Scientific Calculator with memory, history and keyboard support.