i need to Determine the point at which the graph of the function has a horizontal tangent line in this: f(x)=3x^2/x^2+7........i apparently need a (x,y) value. but i can't figure it out no matter what i do. can someone please assist?
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Deb,
Did you mean (3*x^2)/(x^2+7)? If so, look at a graph of the function here:
http://www.wolframalpha.com/bing/?i=%283*x^2%29%2f%28x^2%2b7%29
f(x) (or y) is positive for all x and the function is symmetrical about the Y-axis. Therefore, you can see that if you draw a tangent line at any point on the graph, it will not be parallel to the X-axis (horizontal) except for one point, which is (x,y) = (0,0).
Did you mean (3*x^2)/(x^2+7)? If so, look at a graph of the function here:
http://www.wolframalpha.com/bing/?i=%283*x^2%29%2f%28x^2%2b7%29
f(x) (or y) is positive for all x and the function is symmetrical about the Y-axis. Therefore, you can see that if you draw a tangent line at any point on the graph, it will not be parallel to the X-axis (horizontal) except for one point, which is (x,y) = (0,0).