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    domain of functions 3

    how do you find the domain of the function f(x)=9-x over the square root of x+7
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  2. #2
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    Quote Originally Posted by bastropgarl View Post
    how do you find the domain of the function f(x)=9-x over the square root of x+7
    Hi bastropgarl,

    f(x)=\frac{9-x}{\sqrt{x+7}}

    The denominator cannot = 0. f(x ) would be undefined.

    x + 7 cannot be negative within the set of real numbers. You would have the square root of a negative number.

    So, x + 7 > 0


    Therefore, the domain = {x | x > -7}.
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