Sin is followed by an angle, such as sin30, which is equal to 1/2.

Or radians, because angles can be converted into radians, such as 180 = π (radians).

30 = π/6 (radian)

So sin (π/6) = sin30 = 1/2.

Since x is not an angle, it is radian.

If the number is 2, add a number after X. It depends on what form it is added.

1. if it is sin (x+2) = y.

That is to say, the sine value of (x+2) radian is equal to y.

2. if it is sin x +2=y

That is to say, the sine of x radians plus 2 equals y.