Re: Numerical Methods - Error propagation and avoiding cancellation
Originally Posted by CourtneyMoon
Simplify (x+sqrt(y))(x-sqrt(y)) & use result to derive a method for avoiding cancellation when solving quadratic equations.
So (x+sqrt(y))(x-sqrt(y)) simplified is x²-y but where do I go from there?
When you use the quadratic formula the roots are:
if one of these calculations will result in the subtraction of two nearly equal numbers leading to a loss of precision. This can be avoided by using the simplification you quote, since: