Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!watmath!clyde!floyd!harpo!decvax!yale-com!leichter From: leichter@yale-com.UUCP (Jerry Leichter) Newsgroups: net.math Subject: Re: need help Message-ID: <2844@yale-com.UUCP> Date: Fri, 3-Feb-84 14:06:39 EST Article-I.D.: yale-com.2844 Posted: Fri Feb 3 14:06:39 1984 Date-Received: Wed, 8-Feb-84 06:06:59 EST References: mgweed.6686 Lines: 8 The request was for a way to compute arcsin(x), given sin(x). This is actually quite easy. Given x, you want y = arcsin(x); or, inverting the equation, you want to solve for y, given sin(y) = x. A Newton-Raphson approximation should be quite effective. Recall that to solve f(y)=x for y, you will need to be able to compute f and its first derivative. Since f=sin, you have that; and f'=cos, which you also have since cos(x)=sin(90-x) (in degrees). -- Jerry