Explaination why `sin(0)=0`

requires to refer to the function definition.

`sin(α)`

has been defined as:

Lets suppose that: __alpha angle__ goes to zero (`α -> 0`

) and __adjacent side__ is constant (`b = const`

).

It causes: __opposite side__ goes to zero too (`a -> 0`

) and __hypotenuse side__ goes to __adjacent side__ (`h -> b`

). When angle is equal to `0`

and `a`

is equal to `0`

then `0`

divided by `h`

is equal to `0`

. It means `sin(0)`

is equal to `0`

acording to above definition.

Simple visualisation is presented on below picture: