Do you use RAD or DEG for Trig?
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Do you use RAD or DEG for Trig?
When expressing arguments of trigonometric functions in Mastering assignment answers, use radians unless the question specifically asks you to answer in degrees. /180.
How do you denote a radian?
In SI, the radian is defined as having the value 1. As a consequence, in mathematical writing, the symbol “rad” is almost always omitted. When quantifying an angle in the absence of any symbol, radians are assumed, and when degrees are meant, the degree sign ° is used.
How do you find the sin and cos of an angle in a unit circle?
Using the unit circle, the sine of an angle t equals the y-value of the endpoint on the unit circle of an arc of length t whereas the cosine of an angle t equals the x-value of the endpoint. The sine and cosine values are most directly determined when the corresponding point on the unit circle falls on an axis.
What are the units of cosine of an angle?
Sines and cosines for special common angles
Degrees | Radians | cosine |
---|---|---|
90° | π/2 | 0 |
60° | π/3 | 1/2 |
45° | π/4 | √2 / 2 |
30° | π/6 | √3 / 2 |
Why are radians Unitless?
If a central angle subtends an arc that is equal to the radius of the circle (Figure ), then the central angle has a measure of one radian. Because both q and r are in the same units, when q is divided by r in the preceding formula, the units cancel. Therefore, radian measure is unitless.
Why do we use radian measure?
Radians make it possible to relate a linear measure and an angle measure. The length of the arc subtended by the central angle becomes the radian measure of the angle. This keeps all the important numbers like the sine and cosine of the central angle, on the same scale.
How do you find radians on a unit circle?
The radian measure of an angle is the ratio of the length of the arc to the radius of the circle (θ=sr) ( θ = s r ) . In other words, if s is the length of an arc of a circle, and r is the radius of the circle, then the central angle containing that arc measures radians.