Postby Doubleshadow » Tue Feb 14, 2006 6:52 pm
Range of an equation is what y values the graph has. I usually just reason it out by looking at the graph. For example:
y = x + 1 The graph extends infinitely in both vertical (and in this case, horizontal) directions, so its range is from negative to positive infinity. (-Â¥ ,Â¥ )
y = X^2 (x squared) Here, the graph is from 0 to positive infinity, and includes zero. [0,Â¥ ) Note the bracket versus the parentheses.
Typically, if the range is limited, it will be from a given number to one of the infinities.
y = x^2 + 6 Here, the range is from [6, ¥ ). The y-intercept is the vertex of the graph, and very obviously its lowest point.
Did that help and any other specific questions?
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