Does anyone understand Arcsin? What is it exactly?

Answer 1

It's the invese of the sine function.
If y=sin(x) then
x=arcsin(y)

Answer 2

Yes, second answer is correct**. The reason it's called arcsin is that when trigonometry was first invented, for use in navigation, they didn't use angles, they imagined the sky as the surface of a sphere and used "the sine of an arc". With a fixed radius, the length of arc depends solely on the size of the angle, and vice versa, so you can talk about the sine of an arc or, in reverse, "the arc which has this sine"

** and of course so are all the others put in after that!

Answer 3

arcsin is equavalent to sin^-1 and is used when you have the lengths of the sides of the triangle but not the angle so arcsin(1/2)=30 degrees or arcsin(squareroot(3)/2)= 60 degrees

Answer 4

Arcsin means "the angle whose sine is..."
sin(30°) = 0.5
sin(150°) = 0.5
arcsin(0.5) = 30°, 150°, etc

sin(-30°) = -0.5
sin(-150°) = -0.5
arcsin(-0.5) = -30°, -150°, etc

Because the sine function is a repeating function, many angles may have the same value of sine, so arcsin is called a multi-valued function. By convention we usually use only the angle in the first quadrant for positive values, and 4th quadrant for negative values, as these are the smallest numbers.

Answer 5

It's the reverse of the sin function, answering the question, what is the ANGLE that has the given sin value.

Answer 6

it's the inverse of sin

in the calculator it might show like sin^-1

example: arcsin(sin x) = x