document.write( "Question 1068968: Can you have a function if the answer includes a sq root? for example y= sqrt (x-3) Doesn't this answer include both negative and positive because of the sqrt? Can you explain why? Thanks. \n" ); document.write( "

Algebra.Com's Answer #684204 by rothauserc(4718) $\"\"$ $\"About$

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A function is a relation from a set of inputs to a set of possible outputs where each input is related to exactly one output
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\n" ); document.write( "Consider the ordered pair (x, y) where x is an element in the set X and y is an element in y such that f(x) = y, f is a function then there can be only one ordered pair with the same value of x.
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\n" ); document.write( "We exclude negative values for x, since square root of negative number is an imaginary number
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\n" ); document.write( "For any non-negative real number x, there is one and only one non-negative real number s^2 such that s^2=x. (For example: If x=16, then s=4.) This is called the principal square root of x.
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\n" ); document.write( "y = sqrt (x-3) is a function for all x > or = 3
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