#### Question

# Finding the domain of a radical function?

can someone thoroughly explain to me (not give me the answer) on how to find the domain of a radical function with an index, like for example 3rd root of (t+4) where the 3 is the index, or 4th root of (x^2 + 3x)?

#### Answers

The domain of a radical depends on its index. If it's index is even, than the resulting number inside the radical must be positive, so the domain will be all the numbers that, when put in the expression, result in a number greater than or equal to 0. For example, the domain of the square root of (x+5) is: x is greater than or equal to -5.

The domain of a radical with an odd index is all real numbers, unless the radical appears in the denominator of an expression, in which case the denominator of that expression can't equal 0.

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