Changing the Subject / Manipulating Surds FAQ

1. Why do denominators with surds in them have to be rationalised?

Because it is much easier to deal with surds when they are in the numerator rather than the denominator of an algebraic fraction.

2. How can I solve an equation with surds in?

The best way often is to square both sides of the equation, as squaring is the opposite operation to taking a square root.