Hi, The taylor for cos^-1 goes: cos^-1(x) = Pi/2- (x + 1/2*x^3/3 + 1/2*3/4*x^5/5 + 1/2*3/4*5/6*x^7/7 ...) (which in fact is simply Pi/2 - sin^-1) The results are very good for small x. For x close to 1 you need many many elements of that series to (...) (26 years ago, 9-Mar-99, to lugnet.robotics.handyboard)
A Taylor series isn't the way to go: they converge far too slowly. Here is a polynomial fit to arccos(x): arccos(x) ~ = 1.5708 - 1.0927 x + 4.358 x^3 - 0.8340 x^5 It differs from the exact value of arccos(x) by no more that 0.08 radians (4.6 (...) (26 years ago, 9-Mar-99, to lugnet.robotics.handyboard)
