arcsin can be approximated by the following
1*3*...*(2v-1) x^(2*v+1)
arcsin x= x+(infinite sum, v=0) --------------- * ---------
2*4*...*(2v) 2v*1

quote:Original post by grhodes_at_work
asin and acos are periodic functions, which repeat every 2pi radians. Even though they take parameters from 0 to infinity you can always find a parameter within the range 0 to 2pi that has exactly the same sine and cosine values as your value, no matter how large.

Very, very not true. You''re thinking of sin() and cos().

asin() and acos(), being inverses of the sin() and cos() funcs, take in values between -1 and 1. asin() outputs a value between -pi/2 and pi/2, while acos() outputs a value between 0 and pi (even though there are many possible returns ot the function)*.

atan() does take values from -infinity to infinity, however. It will output a value between -pi/2 and pi/2.

~ Dragonus

* There are an infinite number of solutions to the equations y = asin(x) and y = acos(x) for all x between -1 and 1. Just as sin(0) = sin(pi) = sin(2pi) = 0, since asin() is the inverse of sin(), asin(0) = {..., 0, pi, 2pi, ...}. However, since we can only have one return value from the function rather than an infinite number, we select the most common value, 0, as the return value.