2nd sin

[matkenis]

Hey guys, so today i came across this little problem. I cant figure out, wich function is 2nd sin.

for example, if we have the angle, thats fine, we can just use sin(angle). sin(45) = 0,707
But what if i have the answer in length, for example 2nd sin(0,707) = 45 degress?
So in this example i have 0,707. How do i use it to get the angle?

Its kinda difficult to explane.. :D

-Thank you!! :))

[shadowmouse]

I think you're looking for arcsine. http://www.cplusplus.com/reference/cmath/asin/

[matkenis]

@shadowmouse Yes! Thats what i was looking for, thank you!:)

[Duthomhas]

It's not "2nd" sine, it's inverse sine.

Mathematicians tend to write that as "sin^-1".

    sin 45° = 0.707

    sin^-1 0.707 = 45°

It is also called "arc sine", and in C and C++ you can compute it using the std::asin() function (#include <cmath>).

Hope this helps.

[edit] All the C math functions take angles in radians, so be sure to convert!

[matkenis]

@Duoas Yeah, thanks for the breaf explanation! Yeah, i multiplied my radians by 57 to get degress.

@Duoas
@shadowmouse

-Thanks to you both!:)