I am converting some radians to degrees. I would assume that sin(1°) = sin(pi/180) yes? Since 1°=pi/180. So by algebraic defaults, this should hold true..

But I am getting strange values in these three calculations:
sin-356° - Wolfram|Alpha

sin4° - Wolfram|Alpha

sin364° - Wolfram|Alpha

They all state that the respected degrees equal pi/45 rad..

To my knowledge, $\displaystyle \frac{\pi}{45}=4\deg$ which holds true for the 2nd calculation in my row there.

However, if I convert 364 degrees to radians I do it like this: $\displaystyle 1deg=\frac{\pi}{180}$ so $\displaystyle 364deg=\frac{364\cdot \pi}{180}$ which I do not understand how becomes $\displaystyle \frac{\pi}{45}$

It's probably just some fundamental issue that I am overlooking as usual, but I would appreciate some direction here. Thanks.

2. ## Re: Confused in radians

When a ray starts from x axis and rotates in anticlockwise direction and completes one round it covers 360 degree or 2 pi radian. in case the angle is more than 360 degree or 2 pi we just consider the angle between 0 and 360 degree or 0 and 2 pi. For example if we have 390 degree we consider 390 -360 = 30 degree only. Further we know that angle measured in clockwise direction is considered negative. Thus if we have angle 356 degree it is the same as -4 degree and 364 degree is the same as 4 degree.

3. ## Re: Confused in radians

Originally Posted by ibdutt
When a ray starts from x axis and rotates in anticlockwise direction and completes one round it covers 360 degree or 2 pi radian. in case the angle is more than 360 degree or 2 pi we just consider the angle between 0 and 360 degree or 0 and 2 pi. For example if we have 390 degree we consider 390 -360 = 30 degree only. Further we know that angle measured in clockwise direction is considered negative. Thus if we have angle 356 degree it is the same as -4 degree and 364 degree is the same as 4 degree.
Ah, I see. Thanks.