what's the difference beetween degrees and radians? I had a look and typed in 360º on radians mode and nothing happened. Please help.
It's two different measurements, like kilometers and miles are.
Around the circle it's 360° or 2π radians, 360°/4 = 90° is the same as 2π/4 = π/2.
Since the values for each angle differ between degrees and radians, the given angle for sinus, cosinus and tangens will be different if you don't switch into radian or degree mode on the calculator.
Degrees are an abitrary way of measuring angles but radians are absolute.
To explain : Someone a couple of thousand years ago decided to split a circle up into 360 segments and 'degrees.' Probably because of the (almost) number of days in the year. This is a completely abitrary way to split up the circle,for example they could have chosen to split it up into 500 'degrees' if they had wanted to. So ,in short,degrees do not always work,depending on the type of problem you are working on.
Radians always work. Why? Because their definition makes them absolute.
The definition of one radian is the angle that subtends an arc whose length is exactly the length of the radius of that circle. Or maybe easier to follow ...
............ If arc length = same length as radius of its circle, angle subtended is one radian.
Since the total circumference of a circle is 2 pi radii there are 2 pi radians in a circle. We did not just abitrarily split the circle up into any old number of degrees,we measured the angle using the property of the circle itself.
...and to convert between radians and degrees, 2pi radians = 360 degrees.
