Final answer:
Converting a rational expression to a radical expression doesn't usually involve multiplying by conjugates, dividing the numerator by a radical, or adding the numerator and denominator. However, taking the square root of both the numerator and denominator can generate a radical, if the terms under the square root are perfect squares.
Step-by-step explanation:
To convert a rational expression to a radical expression, you have to understand what these expressions mean in the first place. A rational expression is a fraction in which the numerator and/or the denominator are polynomials. A radical expression has a square root, cube root, etc.
However, answering your choices: a) Not all rational expressions contain radicals to use the concept of conjugates. b) Dividing the numerator by the radical is not the typical transformation between these kinds of expressions. c) Adding the numerator and denominator together doesn't usually result in a radical expression. d) Taking the square root of both numerator and denominator indeed can generate a radical, if the terms under the square root sign are perfect squares.
For instance, you can convert the rational expression 4/9 to a radical expression by taking the square root of both the numerator and denominator, resulting in 2/3.
Learn more about Rational to Radical Conversion