Create a rational function with the following properties

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To create a rational function with a horizontal asymptote at y = 2, the degrees of the numerator and denominator must be equal, with the leading coefficient of the numerator being 2. The vertical asymptotes at x = -3 and x = 1 indicate factors of (x + 3) and (x - 1) in the denominator. To achieve x-intercepts at -1 and 5, the numerator must include factors that yield these roots. The current formulation of the function is y = 2(x + 1)(x - 5) / [(x + 3)(x - 1)], fulfilling all specified properties. This function effectively meets the requirements for horizontal and vertical asymptotes, as well as the x-intercepts.
Painguy
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Give a formula for a rational function having the following properties:
• Horizontal Asymptote: y = 2
• Vertical Asymptotes: x = − 3 and 1
• x-intercepts: -1 and 5

Here is what I've done so far

\frac{2x^2}{(x+3)(x-1)}

I basically get stuck when trying to come up with something for the x intercepts. I hope its not something obvious :P. I've been missing a lot of obvious things today haha.
 
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You've done well to answer the first two points :smile: Just to expand on the ideas of each point, to have a horizontal asymptote of y=2, the degree of the numerator and denominator need to be equal and the coefficient of the highest power (the constant multiplier of x2) needs to be 2. Basically you've done this already, but to fill out the last point we need to change things a bit of course.

For the third, to find the x-intercepts we always let y=0, right? Ok so we have

y=\frac{2x^2}{(x+3)(x-1)}

so far. If we let y=0 then we can see that to solve for x, it doesn't matter what is in the denominator, all we need to consider is what is in the numerator - or another way you can think about it is that if we multiply through by (x+3)(x-1) on both sides, then the left side stays 0, while the right side cancels the denominator.

So what we have now is 2(something)=0, where that something, when solved, will give us the x-intercepts -1 and 5.
 
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