Rationalise the denominator means to make the denominator into a rational number.
Answers
Answer:
Rationalizing the denominator" is when we move a root (like a square root or cube root) from the bottom of a fraction to the top.
Answer:
In order to rationalize the denominator, we need to get rid of all radicals that are in the denominator.
Step 1: Multiply numerator and denominator by a radical that will get rid of the radical in the denominator.
If the radical in the denominator is a square root, then you multiply by a square root that will give you a perfect square under the radical when multiplied by the denominator. If the radical in the denominator is a cube root, then you multiply by a cube root that will give you a perfect cube under the radical when multiplied by the denominator and so forth...
Note that the phrase "perfect square" means that you can take the square root of it. Just as "perfect cube" means we can take the cube root of the number, and so forth.
Keep in mind that as long as you multiply the numerator and denominator by the exact same thing, the fractions will be equivalent.
Step 2: Make sure all radicals are simplified.
Some radicals will already be in a simplified form, but make sure you simplify the ones that are not. If you need a review on this, go to Tutorial 39: Simplifying Radical Expressions.
Step 3: Simplify the fraction if needed.
Be careful. You cannot cancel out a factor that is on the outside of a radical with one that is on the inside of the radical. In order to cancel out common factors, they have to be both inside the same radical or be both outside the radical.