March 22nd, 2009, 06:28 AM
Newtons Method for Approximating Roots
Hi, i have this method here that approximates square roots. I was wondering what ppl thought about it and whether it is following a correct algorithm. It seems to work good and gave pretty close approximations for all my test casses. The only issue is on the very first call to the function, if 1 is passed in as a guess it returns bogus numbers.
* Newtons Method for Approx. square roots.
* Accepts 2 doubles.
* Argument 1 is the number to take the square root of.
* Argument 2 is the approximation/guess of the square root.
* x = 1/2( x + A/x) <-- Formula being used.
double approxSQRT(double A, double approx)
approx = (0.5)*(approx + ( A/approx));
//When sequential approximations have a negligable difference the
// approximation should be very close to the actual square root.
if(previous - approx < 0.0000001 )
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