Sin 570 Degrees

Sin, Cos, Tan, Cot of an Angle
Function
Angle (°)

What is sin 570°?

Answer

sin 570° =
−1/2 = −0.5

Angle in radians: 570° = 19π/6. 570° = 360° + 210° — a full turn plus 210°, quadrant III, where sine is negative.

sin 570° = sin(570° − 360°) = sin 210°

sin 210° = sin(180° + 30°) = −sin 30° = −1/2

P(cos 570°, sin 570°) = (−√3/2, −1/2)

Half of an equilateral triangle with side 1: the hypotenuse is 1 and the leg opposite 30° is 1/2.

sin 30° = 1/2

xyOP

P(cos 570°, sin 570°) ≈ (−0.8660, −0.5)

Highlighted: the projection on the y-axis — sine, y = −0.5.

+1 turn: the drawing shows 210°.

All four functions of 570°
FunctionExact valueDecimal
sin 570°−1/2−0.5
cos 570°−√3/2≈ −0.8660
tan 570°√3/3≈ 0.5774
cot 570°√3≈ 1.7321

Reference angle: sin 30° = 1/2

See Also

Sine of nearby angles

FAQ

What is sin 570°?

sin 570° = −1/2 = −0.5

How to remember sin 30°, sin 45° and sin 60°?

Write them as √1/2, √2/2, √3/2: sin 30° = 1/2, sin 45° = √2/2, sin 60° = √3/2. Cosines are the same numbers in reverse order: cos 30° = √3/2, cos 45° = √2/2, cos 60° = 1/2; tan = sin / cos and cot = cos / sin. Here: sin 570° = −1/2 = −0.5.

Why does a calculator show −0.9803 for sin 570?

The calculator is in radian mode (RAD): it takes sin 570 as the sine of 570 radians, sin 570 rad ≈ −0.9803. Switch it to degrees (DEG): sin 570° = −1/2 = −0.5. In radians the value is never undefined: π is irrational, so a whole number of radians never lands exactly on an axis.