document.write( "Question 692560: How can you determine weather a graph is linear and if its a function \n" ); document.write( "
Algebra.Com's Answer #427332 by KMST(5328)\"\" \"About 
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If you are given the graph on an x-y plane, and a vertical straight line touches more than 1 point of the graph, y is not a function of x.
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\n" ); document.write( "If you are given the graph on an x-y plane, and no vertical straight line touches more than 1 point of the graph, y is a function of x.
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\n" ); document.write( "If you are given the graph on an x-y plane, and it is a straight line that is not vertical, y is a linear function of x.
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\n" ); document.write( "If you are given some sort of definition of an x-y relation, but not the graph, it is a bit more complicated.
\n" ); document.write( "If more than one y is assigned to the same x, as in \"x%5E2%2By%5E2=1\", y is not a function of x.
\n" ); document.write( "If there is no more than one value of y assigned to each x, as in \"y=x%5E2\" or \"y=1%2Fx\", y is a function of x.
\n" ); document.write( "If the relation can be expressed in the form \"y=mx%2Bb\" with some constants \"m\" and \"b\", y is a linear function of x.
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