At the end of the universe may be , the proof process of the circle formula is given in (this article has more than 10,000 reads, it seems that everyone is still more interested in this, and I will talk about this today
Isn't it supposed to be 180 here? SoThe area of the circle becomes 180r 2Finish!!! what,** went wrong.
Insert ** here to describe according to the provisions: radian = arc length radius then, arc length = radian * radius, 2 r = (radian of a circle) * r, i.e. 2 = (radian of a circle) In summary: 2 radians = 360°,Radians = 180°(Usually ° is omitted in the formula) then 1 radian = 180 , 1 angle = 180
Why do you say this and that, because sometimes it's 180, and sometimes it's 314. So what's the difference between the two? The key point is that 180 degrees corresponds to the angle, and here corresponds to the radian, according to the above formula, there is radian = 180°. Take a look at the image of sinx: it's clear that here it isRadians, that isx stands for radiansFrom the above formula, it is also easy to convert radians into angles.
Insert **Description here Have3The meaning of 14 and the meaning of 180°, why do the two meanings not conflict with each other in the calculation? Derivation of the conversion formula between radian and angle.
I think the ancients discovered existence in the same way that Newton discovered the law of gravitation. In the case of having a large number of datasets of circumference and diameter, the ancients were surprised to find that the circumference of the circle is proportional to the diameter (2r), and this scale coefficient is a fixed value, so people gave this number a name for convenience, called . So the ancients began to study the nature, and it continues to this day. Many other mathematical symbols also come from this way, just for the convenience of representation, such as ln, e, sin, etc.
For more content, welcome to follow my WeChat *** Ruthless Swordsman of Half Summer Night.
Hotspot Engine Program